phpman > perldoc > Date::Manip::Date(3pm)

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NAME
    Date::Manip::Date - Methods for working with dates

SYNOPSIS
       use Date::Manip::Date;
       $date = new Date::Manip::Date;

DESCRIPTION
    This module works specifically with date objects.

    Although the word date is used extensively here, it is actually somewhat misleading. Date::Manip
    works with the full calendar date (year, month, day, and week when appropriate), time of day
    (hour, minute, second), and time zone. It doesn't work with fractional seconds.

METHODS
    base
    config
    err
    is_date
    is_delta
    is_recur
    new
    new_config
    new_date
    new_delta
    new_recur
    tz  Please refer to the Date::Manip::Obj documentation for these methods.

    calc
           $date2 = $date->calc($delta [,$subtract]);
           $delta = $date->calc($date2 [,$subtract] [,$mode]);

        Please refer to the Date::Manip::Calc documentation for details.

    cmp
           $val = $date1->cmp($date2);

        This compares two different dates (both of which must be valid date objects). It returns -1,
        0, or 1 similar to the cmp or <=> operators in perl. The comparison will automatically
        handle time zone differences between the two dates (i.e. they will be sorted in order as
        they appear in the GMT zone).

        A warning is printed if either of the date objects does not include a valid date.

    complete
           $flag = $date->complete([$field]);

        This tests the date stored in the object to see if it is complete or truncated (see below
        for a discussion of this).

        If no $field is passed in, it returns 1 if the date is complete, or 0 if it was truncated
        and default values have been supplied.

        If $field is passed in, it may be one of: m, d, h, mn, s . It will return 1 if the value for
        that field was specified, or 0 if a default was used.

    convert
           $err = $date->convert([$zone]);

        This converts the date stored in the object to a different time zone. $zone can be the name
        of a time zone. If it is not passed in, the date is converted to the local time zone.

    holiday
           $name = $date->holiday();
           @name = $date->holiday();
           $name = $date->event();

        This returns the name of the holiday if $date is a holiday. If $date is not a holiday, undef
        is returned. If $date is an unnamed holiday, an empty string is returned.

        In scalar context, holiday returns the name of one holiday that occurs on that date (the one
        first defined in the config file). In list context, it returns all holidays on that date.

    input
           $str = $date->input();

        This returns the string that was parsed to form the date.

    is_business_day
           $flag = $date->is_business_day($checktime);

        This returns 1 if $date is a business day.

        $checktime may be passed in. If it is non-zero, the time is checked to see if the date is a
        business day and falls within work hours.

    list_holidays
          @date = $date->list_holidays([$y]);

        This returns a list of Date::Manip::Date objects containing all dates during a year which
        are holidays. The times will all be 00:00:00.

        If $y is not passed in, it will list the holidays in the same year as the date stored in
        $date (if any) or in the current year otherwise.

    list_events
           @list = $date->list_events(       [$format] );
           @list = $date->list_events(0      [,$format]);
           @list = $date->list_events($date1 [,$format]);

        This returns a list of events. Events are defined in the Events section of the config file
        (discussed in the Date::Manip::Holidays manual).

        In the first form, a list of all events active at the precise time stored in $date will be
        returned.

        If the first argument evaluates to 0, a list of all events active at any time during that
        day (Y,M,D) are returned.

        If the first argument is another date object, all events that are active at any time between
        the two dates (inclusive) are returned.

        By default, the list returned is of the form:

           ( [START, END, NAME],
             [START, END, NAME],
             ...
           )

        where START is a date object when an event starts, END is a date object when it ends, and
        NAME is the name of the event. Note that START and END are the actual start and end date of
        the event and may be outside the range of dates being examined (though the event will
        obviously overlap the range or it wouldn't be included in the list).

        If $format is included, it can specify an alternate format for the output. Currently, the
        only supported format is named "dates" and it returns a list in the form:

           ( [DATE1, NAME1a, NAME1b, ...],
             [DATE2, NAME2a, NAME2b, ...],
             ...
           )

        This includes a list of all dates during the range when there is a change in what events are
        active. DATE1 will always be the start of the range being considered, and (NAME1a, NAME1b,
        ...) are the list of all events that will be active at that time. At DATE2, the list of
        active events changes with (NAME2a, NAME2b, ...) being active.

        It is quite possible that a date be included which has no active events, and in that case,
        the list of names will be empty.

    nearest_business_day
           $date->nearest_business_day([$tomorrowfirst]);

        This looks for the work day nearest to $date. If $date is a work day, it is left unmodified.
        Otherwise, it will look forward or backwards in time 1 day at a time until a work day is
        found. If $tomorrowfirst is non-zero (or if it is omitted and the config variable
        TomorrowFirst is non-zero), we look to the future first. Otherwise, we look in the past
        first. In other words, in a normal week, if $date is Wednesday, $date is returned. If $date
        is Saturday, Friday is returned. If $date is Sunday, Monday is returned. If Wednesday is a
        holiday, Thursday is returned if $tomorrowfirst is non-nil or Tuesday otherwise.

    next_business_day
    prev_business_day
           $date->next_business_day($off [,$checktime]);
           $date->prev_business_day($off [,$checktime]);

        The next_business_day method sets the given date to $off (which can be a positive integer or
        zero) business days in the future. The prev_business_day method sets the date to $off
        business days in the past.

        First, $date is tested. If $checktime is nonzero, the date must fall on a business date, and
        during business hours. If $checktime is zero, the time check is not done, and the date must
        simply fall on a business date.

        If the check fails, the date is moved to the start of the next business day (if $checktime
        is nonzero) or the next business day at the current time (if $checktime is zero). Otherwise,
        it is left unmodified.

        Next, if $off is greater than 0, the day $off work days from now is determined.

        One thing to note for the prev_business_day method is that if $date check fails, the date is
        set to the next business date, exactly like next_business_day. In other words, if $date is
        not a business day, the call:

           $date->prev_business_day(0 [,$checktime]);

        moves $date forward in time instead of backward which is nonintuitive, but you just have to
        think of day 0 as being the next business day if $date is not a business day.

        As a result, the following two calls ALWAYS give the same result:

           $date->next_business_day(0 [,$checktime]);
           $date->prev_business_day(0 [,$checktime]);

        no matter what date is stored in $date.

    parse
           $err = $date->parse($string [,@opts]);

        This parses a string which should include a valid date and stores it in the object. If the
        string does not include a valid date, an error is returned. Use the err method to see the
        full error message.

        A full date may include a calendar date (year, month, day), a time of day (hour, minute,
        second), and time zone information. All of this can be entered in many different formats.

        For information on valid date formats, refer to the section VALID DATE FORMATS. For
        information on valid time zone information, refer to the section VALID TIME ZONE FORMATS.

        If no time zone information is included in the date, it is treated as being in the local
        time zone.

        If time zone information is included, the date will be kept in that time zone, and all
        operations will be done in that time zone. The convert method can be used to change the time
        zone to the local time zone, or to another time zone.

        Some things to note:

        All strings are case insensitive. "December" and "DEceMBer" are equivalent.

        When a part of the date is not given, defaults are used. This is described below in the
        section "Complete vs. truncated dates and times".

        The year may be entered as 2 or 4 digits. If entered as 2 digits, it will be converted to a
        4 digit year. There are several ways to do this based on the value of the YYtoYYYY config
        variable. Refer to the Date::Manip::Config documentation for more details.

        Dates are always checked to make sure they are valid.

        If any other arguments are passed in, they act as options which may improve the speed of
        parsing. These include:

           noiso8601  Do not try to parse the
                      date as an ISO 8601 date
                      or time.
           nodow      Do not try to parse a
                      day-of-week (Monday) in
                      the string.
           nocommon   Do not try to parse the
                      date using the formats
                      in the "Common date
                      formats" section.
           noother    Do not try to parse the
                      date using the "Less common
                      date formats" or a time
                      using the "Other time
                      formats".
           nospecial  Do not try to parse the
                      date using the "Special
                      date strings" formats
                      or a time using the
                      "Special time strings"
                      formats, or as a
                      combined date/time using
                      the "Additional combined
                      date and time" formats.
           nodelta    Do not treat deltas as
                      a date relative to now.
           noholidays Do not parse holiday
                      names as dates.

    parse_date
           $err = $date->parse_date($string [,@opts]);

        This parses a string which contains a valid date and sets the date part of the object.

        If the object contained a valid date, the time is kept unchanged. If the object did NOT
        contain a valid date, a time of 00:00:00 is used.

        @opts can be any of the strings described in the parse method above.

    parse_time
           $err = $date->parse_time($string [,@opts]);

        This parses a string and sets the time portion of $date to contain it.

        If the object contained a valid date, the Y/M/D portion is left unchanged. Otherwise, the
        current date is used.

        @opts can be 'noiso8601' or 'noother'.

    parse_format
           $err          = $date->parse_format($format,$string);
           ($err,%match) = $date->parse_format($format,$string);

        This will parse a date contained in $string based on explicit format information contained
        in $format.

        If the format is invalid, $err will contain an error message. If the format is valid, but
        string doesn't match, an error code of 1 is returned.

        If called in array context, a hash will be returned containing %+. This is primarily useful
        if the $format string contains some named capture groups that you define. This is discussed
        below.

        $format is a string containing a regular expression with some special directives (based on
        the printf directives). These directives are turned into regular expression components, and
        then the entire string is turned into a regular expression which, if $string matches it,
        will return the date.

        The directives available are identical to the printf directives. So, if your $format string
        contains the directive '%Y', it will match a 4-digit year.

        All of the printf directives are available here with a few caveats:

           %l        This directive is NOT available.

           %b,%h,%B  These will all match a month name or abbreviation.

           %v,%a,%A  These will all match a day name or abbreviation.

           %z,%Z,%N  These will match any time zone string.

           %n        Multi-line matching is not currently supported,
                     so this directive is not allowed.

           %x        All format directives are converted to a regular
                     expression and then cached (so that a format
                     can be reused without the penalty of doing the
                     conversion to a regular expression with each use).
                     As a result, if you need to set the DateFormat config
                     variable (which determines the meaning of the %x
                     directive), it must be done before a format string
                     containing %x is used. If the DateFormat config variable
                     is set afterwards, the format string will reflect the
                     old, NOT THE NEW, value of DateFormat.

        The format string may not over-specify the date. In other words, you may not include both a
        %y and %Y directive or both a %j and %m directive.

        A valid format string will specify any of the following sets of data:

           Required          Optional

           M D H Mn S        Y Zone Day-of-week
           M D H Mn          Y Zone Day-of-week
           M D               Y Zone Day-of-week
           H Mn S            Zone
           H Mn              Zone

        For example, if you had a date stored as:

           YYYY.MM-DD

        you could match it using the following:

           $date->parse_format('%Y\\.%m\\-%d',$string);

        If you wanted to extract the date from an apache log line:

           10.11.12.13 - - [17/Aug/2009:12:33:30 -0400] "GET /favicon.ico ...

        you could use:

           $date->parse_format('.*?\\[%d/%b/%Y:%T %z\\].*',$line);

        When matching months, days, and hours, there are two directives that could be used (for
        numerical versions). For the month, you may use %m or %f. If your date is known to have a
        two-digit month, you should use %m. If it contains a one- or two-digit month, you must use
        %f (and it is safe to use %f for two-digit months). Similarly, for days, you can use %d or
        %e and for hours you can use %H or %k. In both cases, the first can only be used if you are
        guaranteed a 2-digit value.

        In your format string, you may use capture groups (or back references to them) in the
        regular expression using all of the rules of normal regular expressions. Since Date::Manip
        uses named capture groups internally, it is suggested that you also use named groups. Mixing
        numbered and named groups will work... but it'll be entirely up to you to keep track of what
        numbers refer to which capture groups.

        Every printf directive adds one or more named capture groups to the regular expression. If
        you use named groups in the format string, they must not conflict with the ones used
        internally, or else the date will probably not be parsed correctly.

        The following named capture groups are used internally:

           y
           m
           d
           h
           mn
           s
           mon_name
           mon_abb
           dow_name
           dow_abb
           dow_char
           dow_num
           doy
           nth
           ampm
           epochs
           epocho
           tzstring
           off
           abb
           zone
           g
           w
           l
           u

        To be safe, it is suggested that any additional named capture groups introduced by the
        programmer start with a capital letter. This is guaranteed to never conflict with any
        existing, or future named capture groups.

        In order to get access to the values stored in the additional named capture groups, the
        parse_format function must be called in list context, and the %+ array will be returned as
        the second value.

        As an example:

           $string = "before 2014-01-25 after";
           ($err,%m) = $date->parse_format('(?<PRE>.*?)%Y-%m-%d(?<POST>.*)',$string);

        would return a hash (%m) with the following key/value pairs:

           'PRE'  => 'before '
           'POST' => ' after'

    prev
    next
        The prev method changes the date to the previous (or current) occurrence of either a day of
        the week, a certain time of day, or both. The next method changes the date to the next (or
        current) occurrence. The examples below illustrate the prev method, but the next one is
        identical in operation.

        There are two different ways to use this method. The first is to pass in a day of week and
        possibly a time:

           $err = $date->prev($dow, $curr [,$time]);

        If $curr = 0, this means to look for the previous occurrence of the day of week, and set the
        time to the value passed in (or current time if no time was passed in). The day is ALWAYS
        less than the current day. If the current day is the same day of week as $dow, then the date
        returned will be one week earlier.

        If $curr = 1, it means to look for the current or previous occurrence of the day of week,
        and set the time to the value passed in (or 00:00:00 if none was passed in). If the current
        day of week is the same as $dow, the date will remain unchanged. Since the time is then set,
        the new date may actually occur after the original date depending on the value of $time.

        If $curr = 2, it means to look for the last time (not counting now) that the day of week at
        the given time occurred. The date may be the same as the original date.

        $time may be a list reference of [H,MN,S], [H,MN], or [H].

        The following examples should illustrate the use of this function.

            Original Date = Fri Nov 22 18:15:00

            dow      curr   time       new date

            4 (Thu)  0/1/2  undef      Thu Nov 21 00:00:00
            4        0/1/2  [12,30,0]  Thu Nov 21 12:30:00

            5 (Fri)  0/2    undef      Fri Nov 15 18:15:00
            5        1      undef      Fri Nov 22 18:15:00

            5        0      [12,30,0]  Fri Nov 15 12:30:00
            5        1/2    [12,30,0]  Fri Nov 22 12:30:00

            5        0/2    [19,30,0]  Fri Nov 15 19:30:00
            5        1      [19,30,0]  Fri Nov 22 19:30:00

        The second way to use this method is by passing in undef for the day of week.

           $err = $date->prev(undef,$curr,$time);

        In this case, a time is required and it must be a list reference of 3 elements: [H, MN, S].
        Any or all of the elements may be undef.

        The new date is the previous occurrence of the time.

        If you define hours, then minutes and seconds may be defined, or default to 0 and you are
        looking for a previous time that the specified time (HH:00:00) occurred (which might be as
        much as 24 hours in the past).

        If hours are undefined and minutes are defined, then seconds may be defined, or default to
        0, and you are looking for the last time the minutes/seconds (MN:SS) appeared on the digital
        clock, which will be sometime in the past hour.

        Finally, if hours and minutes are undefined, seconds must be defined (or default to zero)
        and the last time that that second occurred will be returned (which will be sometime in the
        past minute).

        If $curr is non-zero, the current time is returned if it matches the criteria passed in, so
        the returned value will be now or in the past. If $curr is zero, the time returned will
        definitely be in the past.

            DATE = Fri Nov 22 18:15:00

            curr  hr     min    sec      returns
            0/1   18     undef  undef    Nov 22 18:00:00
            0/1   18     30     0        Nov 21 18:30:00
            0     18     15     undef    Nov 21 18:15:00
            1     18     15     undef    Nov 22 18:15:00
            0     undef  15     undef    Nov 22 17:15:00
            1     undef  15     undef    Nov 22 18:15:00

    printf
           $out = $date->printf($in);
           @out = $date->printf(@in);

        This takes a string or list of strings which may contain any number of special formatting
        directives. These directives are replaced with information contained in the date. Everything
        else in the string is returned unmodified.

        A directive always begins with '%'. They are described in the section below in the section
        PRINTF DIRECTIVES.

    secs_since_1970_GMT
           $secs = $date->secs_since_1970_GMT();

        This returns the number of seconds that have elapsed since Jan 1, 1970 00:00:00 GMT
        (negative if the date is earlier).

        The reverse is also allowed:

           $err = $date->secs_since_1970_GMT($secs);

        which sets the date to $secs seconds from Jan 1, 1970 00:00:00 GMT in the local time zone.

    set
           $err = $date->set($field,@vals [,$isdst]);

        This explicitly sets one or more fields in a date.

        $field can be any of the following:

           $field   @vals

           zone     [ZONE]         ZONE can be any zone or alias

           zdate    [ZONE,]DATE    sets the zone and entire date

           date     DATE           sets the entire date

           time     TIME           sets the entire time

           y        YEAR           sets one field
           m        MONTH
           d        DAY
           h        HOUR
           mn       MINUTE
           s        SECOND

        Here, DATE is a list reference containing [Y,M,D,H,MN,S] and TIME is a list reference
        containing [H,MN,S].

        ZONE is optional (it defaults to the local zone as defined either by the system clock, or
        the SetDate or ForceDate config variables). If it is passed in, it can be any zone name,
        abbreviation, or offset. An offset can be expressed either as a valid offset string, or as a
        list reference. Refer to the join/split functions of Date::Manip::Base for information on
        valid offset strings.

        An optional last argument is $isdst (which must be 0 or 1) is included when setting a date
        which could be in either standard time or daylight saving time. It is ignored in all other
        situations. If it is not included, and the resulting date could be in either, it will
        default to standard time.

        The $date object must contain a valid date (unless the entire date is being set with $field
        set to either "zdate" or "date").

        If $field is "zone", the time zone of the date will be set. If ZONE is not passed in, it
        will be set to the local time zone. When setting the time zone, no conversion is done!
        Whatever date and time is stored in the $date object prior to this remains unchanged...
        except it will be that date and time in the new time zone.

        If $field is "zdate", the entire date and time zone is set. If ZONE is not passed in, it is
        set to the local time zone.

        If $field is "date", the entire date will be set, but the time zone of the date will not be
        changed.

        If $field is "time", or one of the individual fields, only those fields will be modified.

        An error is returned if an invalid argument list is passed in, or if the resulting date is
        checked and found to be invalid.

    value
           $val = $date->value([$type]);
           @val = $date->value([$type]);

        These return the value of the date stored in the object.

        In scalar context, a printable string in the form YYYYMMDDHH:MN:SS is returned. In list
        context, a list is returned of (Y,M,D,H,MN,S).

        If $type is omitted, the date is returned in the time zone it was parsed in.

        If $type is "local", it is returned in the local time zone (which is either the system time
        zone, or the zone specified with the SetDate or ForceDate config variables).

        If $type is "gmt", the date is returned in the GMT time zone.

        An empty string or list is returned in the case of an error (and an error code is set).

    week_of_year
           $wkno = $date->week_of_year([$first]);

        This figures out the week number. If $first is passed in, it must be between 1 and 7 and
        refers to the first day of the week. If $first is not passed in, the FirstDay config
        variable is used.

        NOTE: This routine should only be called in rare cases. Use printf with the %W, %U, %J, %L
        formats instead. This routine returns a week between 0 and 53 which must then be "fixed" to
        get into the ISO 8601 weeks from 1 to 53. A date which returns a week of 0 actually belongs
        to the last week of the previous year. A date which returns a week of 53 may belong to the
        first week of the next year.

ISSUES WITH PARSING DATES
    The following issues may occur when parsing dates that should be understood to make full use of
    this module.

    Complete vs. truncated dates and times
        Date formats are either complete or truncated. A complete date fully specifies the year,
        month, and day and a complete time fully specifies the hour, minute, and second.

        It should be understood that in many instances, the information may be implied rather than
        explicitly stated, but it is still treated as complete.

        For example, the date "January 3" is complete because it implies the current year.

        A truncated calendar date or time does not include information about some of the fields.
        Date::Manip will never work with a partial date or time, so defaults will be supplied.

        For example, the date "2009-01" is missing a day field, so a default will be used. In this
        case, the day will be the 1st, so this is equivalent to "Jan 1st 2009". If only the year is
        given, it will default to Jan 1.

        If the time, or any of it's components is missing, they default to 00. So the time "12:30"
        and "12:30:00" are equivalent.

        The "complete" method can be used to check what type of date was parsed, and which values
        were specified (either explicitly or implied) and which were provided as a default. It
        should be noted that there is no way to differentiate between an explicit and implied value.

        A string with a date and/or time may consist of any of the following:

           a complete date and a time (complete or truncated)
           a truncated date with no time
           a time (complete or truncated) with no date

        In other words, the date "Jan 2009 12:30" is not valid since it consists of a time with a
        truncated date.

VALID TIME ZONE FORMATS
    When specifying a time zone, it can be done in three different ways. One way is to specify the
    actual time zone. The second is to supply a valid time zone abbreviation. The third is to
    specify an offset (with an optional abbreviation). The following dates illustrate the these
    formats.

    The timezone information always follows the time immediately, and may only be included if a time
    is included. The following examples use an ISO 8601 format for the date/time, but any of the
    other date and time formats may be used.

    The first way to specify the time zone is to specify it by complete name (or using one of the
    standard aliases):

       2001-07-01-00:00:00 America/New_York

    Although this is unambiguous when it comes to determining the time zone, the time is ambiguous
    in most zones for one hour of the year. When a time change occurs during which the clock is
    moved back, the same wall clock time occurs twice.

    For example, in America/New_York, on Sunday, Nov 2, 2008, at 02:00 in the morning, the clock was
    set back to 01:00. As a result, the date Nov 2, 2008 at 01:30 is ambiguous. It is impossible to
    determine if this refers to the 01:30 that occurred half an hour before the time change, or the
    one 30 minute after the change.

    In practice, if this form is used, the date will be assigned to standard time, meaning that
    there will be some times (typically 1 hour per year) which cannot be expressed this way. As
    such, this method is discouraged.

    The second way to specify the time zone, which is the most common, is to use a time zone
    abbreviation:

       2001-07-01-00:00:00 EDT

    Unfortunately, the abbreviation does not uniquely determine the time zone except in a few cases.
    In order to assign a time zone, Date::Manip will refer to a list of all time zones which use the
    abbreviation. They will be tested, in the order given in the Date::Manip::Zones documentation,
    and the first match (i.e. the one in which the given date/time and abbreviation are valid)
    determines the time zone which will be used. A great deal of effort has been made to ensure that
    the most likely time zone will be obtained (i.e. the most common time zones are tested before
    less common ones), so in most cases, the desired results will be obtained.

    If the default order does not yield the desired time zone, the order of testing can be modified
    using the abbrev method described in the Date::Manip::TZ documentation.

    Although the time zone is ambiguous, the date is not, since only time zones for which the date
    are valid will be used.

    The third way to specify the time zone is by specifying an offset and an optional abbreviation:

       2001-07-01-00:00:00 -04
       2001-07-01-00:00:00 -0400
       2001-07-01-00:00:00 -040000
       2001-07-01-00:00:00 -04:00
       2001-07-01-00:00:00 -04:00:00

       2001-07-01-00:00:00 -04 (EDT)
       2001-07-01-00:00:00 -0400 (EDT)
       2001-07-01-00:00:00 -040000 (EDT)
       2001-07-01-00:00:00 -04:00 (EDT)
       2001-07-01-00:00:00 -04:00:00 (EDT)

       2001-07-01-00:00:00 -04 EDT
       2001-07-01-00:00:00 -0400 EDT
       2001-07-01-00:00:00 -040000 EDT
       2001-07-01-00:00:00 -04:00 EDT
       2001-07-01-00:00:00 -04:00:00 EDT

    The offset almost never sufficient to uniquely determine the time zone (and it is not even
    guaranteed that both the offset and abbreviation will, though in practice, it is probably
    sufficient). In this instance, the time zone will be determined by testing all time zones which
    have the given offset (and abbreviation if it is included) until one is found which matches both
    pieces of information. For more information about how this testing is done, refer to the
    def_zone method of the Date::Manip::TZ documentation.

VALID DATE FORMATS
    There are several categories of date formats supported by Date::Manip. These are strings which
    specify only the year/month/day fields.

    These formats explicitly set the date, but not the time. These formats may be combined with a
    time string (as specified below) to set both the date and time. If this is not done, the default
    time is determined by the DefaultTime config variable.

    ISO 8601 dates
        The preferred date formats are those specified by ISO 8601. The specification includes valid
        calendar date and valid time formats. Date::Manip will handle all of these formats, but does
        not require that the dates rigidly adhere to the specification since the ultimate goal of
        Date::Manip is to handle dates as they are represented in real life and some common
        variations exist which are similar to, but not identical to, those from the specification.

        A calendar date includes the following fields:

           CC    2-digit representation of the century
           YY    2-digit representation of the year in
                 a century
           MM    2-digit representation of a month
           DD    2-digit representation of a day of month
           DoY   3-digit representation of a day of year
                 (001-366)
           Www   the character "W" followed by a 2-digit
                 week of the year (01-53)
           D     the day of the week (1-7)

        The following date formats are considered complete by Date::Manip. In the following, the
        date Thu Mar 5 2009 is used as an example. This is the 64th day of the year. Thu is the 4th
        day of the week. The week starting Mon, Mar 2 is the 10th week of the year (according the
        the ISO 8601 definition). Obviously, some of the formats are only valid when used at some
        times. For example, the format --MMDD refers to a month and day in the current year, so the
        date Mar 5, 2009 can only be specified using this format during 2009.

           Format      Notes   Examples

           CCYYMMDD            20090305
           CCYY-MM-DD          2009-03-05

           YYMMDD      1,2,4   090305
           YY-MM-DD            09-03-05

           -YYMMDD     3,4     -090305
           -YY-MM-DD           -09-03-05

           --MMDD      1       --0305
           --MM-DD             --03-05

           ---DD       1       ---05


           CCYYDoY             2009064
           CCYY-DoY            2009-064

           YYDoY       1,4     09064
           YY-DoY              09-064

           -YYDoY      3,4     -09064
           -YY-DoY             -09-064

           -DoY        1       -064


           CCYYWwwD            2009W104
           CCYY-Www-D          2009-W10-4

           YYWwwD      1,4     09W104
           YY-Www-D            09-W10-4

           -YYWwwD     3,4     -09W104
           -YY-Www-D           -09-W10-4

           -YWwwD      1       -9W104
           -Y-Www-D            -9-W10-4
                               Y is the year (0-9) in
                               current decade

           -WwwD       1       -W104
           -Www-D              -W10-4

           -W-D        1       -W-4
                               D is day (1-7) in
                               current week

           ---D        1       ---4
                               same as -W-D

        The following date formats are truncated:

           CCYY-MM     2       2009-03   (2009-03-01)

           CCYY                2009      (2009-01-01)

           CC          2       20        (2000-01-01)

           -YYMM       4       -0903
           -YY-MM              -09-03

           -YY         4       -09

           --MM                --03

           CCYYWww             2009W10
           CCYY-Www            2009-W10

           YYWww       4       09W10
           YY-Www              09-W10

           -YYWww      3,4     -09W10
           -YY-Www             -09-W10

           -Www                -W10

        Notes:

        1 These formats are considered truncated in the standard, but since they do include (or
        imply, using the current date for defaults) all of the fields, and since they do not
        introduce any parsing complexities, the standard is relaxed, and they are treated as
        complete.

        2 These formats are treated differently than in Date::Manip 5.xx as described below.

        3 These formats are not defined in the ISO 8601 spec, but are added for the sake of
        completeness since they do not add any parsing incompatibilities.

        4 Formats where the century is not given are described as a year in the current century in
        the specification. Date::Manip treats this more generically using the YYtoYYYY config
        variable. This will be used to determine how to determine the full year.

        Date::Manip 5.xx handled ISO 8601 dates in a less rigid fashion, and deviated from the
        specification in several formats. As of 6.00, the specification is followed much more
        closely so that all of the date formats included in it should produce valid dates. This
        changes, in a backwards incompatible way, the way a few strings will be interpreted as
        dates.

        As of 6.00, a two-digit date will be treated as CC. Previously, it was treated as YY.

        A six-digit date will be treated as YYMMDD. Previously, it was treated as YYYYMM.

        Previously, dashes were treated as optional in many cases. According to the specification,
        dates may be written in expanded form (with all dashes present) or abbreviate form (with no
        dashes). As of 6.00, this is the behavior, so the formats: YYMMDD and YY-MM-DD are allowed,
        as per the specification, but the format YY-MMDD is NOT allowed (though it was previously).

        The Www-D formats require a bit of explanation. According to the specification, the date:

           1996-w02-3

        refers to the day with an ordinal number of 3 within the calendar week in the 2nd week of
        1996.

        In the specification, the days of the week are numbered from 1 to 7 (Monday to Sunday), and
        the week always begins on Monday, so day 1 (Monday) is always the first day of the week, day
        2 (Tuesday) is always the second day of the week, etc.

        In Date::Manip, the constraint that the week must start with Monday is relaxed, allowing the
        week to begin with Sunday (a far more common start of the week in calendars, at least in
        some parts of the world).

        This presents a problem though in that the above date could be interpreted as Wednesday (day
        3) of the 2nd week of 1996, or as the 3rd day of the 2nd week of 1996 (which would normally
        be Wednesday, but would be Tuesday if the week begins on Sunday).

        As of Date::Manip 6.00, the above date will be interpreted as the 3rd day of the 2nd week.
        This is a reversal from Date::Manip 5.xx, but I believe is what the specification would
        require. For more information, refer to the Date::Manip::Changes document.

    Common date formats
        Date::Manip supports a number of common date formats. The following fields may be included
        in a date:

          YY    2-digit representation of the year
          YYYY  4-digit representation of the year
          M     1- or 2- digit representation of the month
          MM    2-digit representation of the month
          D     1- or 2- digit representation of the day
          DD    2-digit representation of the day
          mmm   The abbreviated or full month name (i.e. Jan)

        The following date formats are supported:

           Format      Notes   Examples

           M/D         1,2,3   3/5
           M/D/YY      1       3/5/09
           M/D/YYYY    1       3/5/2009

           YYYY/M/D            2009/3/5

           mmm/D               Mar/5
           mmm/D/YY            Mar/5/09
           mmm/D/YYYY          Mar/5/2009
           D/mmm               5/Mar
           D/mmm/YY            5/Mar/09
           D/mmm/YYYY          5/Mar/2009
           YYYY/mmm/D          2009/Mar/5

           mmmD                Mar5
           mmmDDYY     4       Mar0509
           mmmDDYYYY           Mar052009
           Dmmm                5Mar
           DmmmYY              5Mar09
           DmmmYYYY            5Mar2009
           YYYYmmmD            2009Mar5

           mmmD YY             Mar5 09
           mmmD YYYY           Mar5 2009
           Dmmm YY             5Mar 09
           Dmmm YYYY           5Mar 2009

           mmm/D YY            Mar/5 09
           mmm/D YYYY          Mar/5 2009
           D/mmm YY            5/Mar 09
           D/mmm YYYY          5/Mar 2009

           YY   mmmD           09   Mar5
           YYYY mmmD           2009 Mar5
           YY   Dmmm           09   5Mar
           YYYY Dmmm           2009 5Mar

           YY   mmm/D          09   Mar/5
           YYYY mmm/D          2009 Mar/5
           YY   D/mmm          09   5/Mar
           YYYY D/mmm          2009 5/Mar

           YYYY:MM:DD          2010:01:15 (EXIF format)

           mmmYYYY     4       Jun 2010
           YYYYmmm     4       2010 June
           mmm/YYYY    4       Jun/2010
           YYYY/mmm    4       2010/Jun

        In the formats above, the slash (/) can be replace by any of the valid separators:
        whitespace, slash (/), period (.), or dash (-). The dash, though allowed, is discouraged
        since it may conflict with an ISO 8601 format. For example, the format MM/DD/YY is just
        fine, but MM-DD-YY does not work since it conflicts with YY-MM-DD. To be safe, if "-" is
        used as a separator in a non-ISO format, they should be turned into "/" before calling the
        Date::Manip routines or you should use the 'noiso8601' option with the parse or parse_date
        methods.

        No matter what separator is used, the same separator must be used throughout the date. For
        example, MM/DD/YY is valid and MM.DD.YY is also valid, but MM/DD.YY is NOT valid.

        Notes:

        1 With these formats, Americans tend to write month first, but many other countries tend to
        write day first. The latter behavior can be obtained by setting the config variable
        DateFormat to something other than "US".

        2 The dot (.) separator may not be used in the M/D format since it will be interpreted as
        the H12,H+ format described below.

        3 The M/D format should not use the period (.) separator as that will incorrectly match the
        HH,H+ time format.

        4 Historically, I have not supported partial dates (i.e. dates that were not fully
        specified), but it has been argued that something like 'Jun 1910' would be interpreted by
        almost everyone as a day in June of 1910 instead of June 19, 2010. And it has been shown
        that in some applications, dates are specified in that way. I have added the new config
        variable Format_MMMYYYY which will change this. If this variable is not set, the formats
        allowed are:

              mmmDDYY

           If it is set, the formats allowed are:

              mmmYYYY
              YYYYmmm

           The day of week may not be included with these formats.  When
           parsing a full date/time, if Format_MMMYYYY is set to 'first',
           it returns the 1st of the month at midnight.  If it is set to
           'last', it returns the last day at 23:59:59.  If parsing only
           only a date, it will be set to the first or last day of the
           month at midnight.

        These formats explicitly set the date, but not the time. The default time is determined by
        the DefaultTime config variable.

    Less common date formats
        The following formats are also supported by Date::Manip:

           DoW
                The day of week of the current week
                   Friday
                   Friday at 12:40

           MMM Nth [YYYY]
           Nth MMM [YYYY]
           YYYY MMM Nth
           YYYY Nth MMM
                Dec 1st 1970
                1st Dec 1970
                1970 Dec 1st
                1970 1st Dec

           next/prev DoW
                The next or last occurrence of DoW
                   next Friday
                   last Friday at 12:40

           next/last week/month/year
                The day one week/month/year from now
                or in the past
                   next week
                   last month at 15:00

           last day in MMM [YYYY]
                The last day of the month
                   last day in October
                   last day in October 1996

           last DoW in MMM [YYYY]
                The last DoW in the month
                   last Tuesday in October
                   last Tuesday in October 1996

           last DoW in YYYY
                The last DoW in the year
                   last Tuesday in 1997

                   NOTE: "last DoW" doesn't work in
                   English since the word "last"
                   is used for both this expression
                   and for "prev DoW", which gets
                   parsed first. "last DoW" MAY
                   work in other languages.

           Nth DoW in MMM [YYYY]
                The Nth DoW in the month
                   3rd Tuesday in October
                   3rd Tuesday in October 1996

           Nth DoW [YYYY]
                The Nth DoW in the year
                   22nd Sunday
                   22nd Sunday in 1996

           Nth day in MMM [YYYY]
                The Nth day of the month
                   1st day of February
                   1st day of February 2012

           DoW week
                British: same as "in 1 week on DoW"
                   Monday week

           DoW week N [YYYY]
           Dow Nth week [YYYY]
                Sunday week 22
                Sunday 22nd week
                   These refer to the day of week
                   of the Nth week of the year.

           Nth
                12th
                   This refers to the Nth day of the
                   current month.

        Note that the formats "Sunday week 22" and "22nd Sunday" give different behaviors. "Sunday
        week 22" returns the Sunday of the 22nd week of the year based on how week 1 is defined. ISO
        8601 defines week one to contain Jan 4, so "Sunday week 1" might be the first or second
        Sunday of the current year, or the last Sunday of the previous year. "22nd Sunday" gives the
        actual 22nd time Sunday occurs in a given year, regardless of the definition of a week.

    Special date strings
        Most languages have strings which can be used to specify the date (relative to today). In
        English, these include the strings:

           today
           tomorrow
           yesterday

        There is also support for the British formats:

           today week
           tomorrow week
           yesterday week

        which refer to one week after today/tomorrow/yesterday respectively.

        Other languages have similar strings.

    Holidays
        You can parse holiday names as dates (including timezones). For example:

           Christmas
           Christmas 2010
           Christmas 2010 at noon
           Christmas 2010 at noon PST
           Saturday Christmas 2010 at noon

    In all of the formats (except for ISO 8601 formats), the day of week ("Friday") can be entered
    anywhere in the date and it will be checked for accuracy. In other words,

      "Tue Jul 16 1996 13:17:00"

    will work but

      "Jul 16 1996 Wednesday 13:17:00"

    will not (because Jul 16, 1996 is Tuesday, not Wednesday).

A NOTE ABOUT FOREIGN LANGUAGE DATES
    Although Date::Manip has some support for parsing dates in foreign languages, it must be noted
    that the formats supported are largely based on English equivalents.

    There are probably many different dates that are perfectly valid, and in common usage, in other
    languages which do not have an equivalent in the English language, and unfortunately,
    Date::Manip will probably not parse these.

    You are free to send these to me, and I'll see if there is a way to add them in, but I do not
    guarantee anything. Without having a full-blown language parser (or at least the portion of the
    language that is devoted to calendar and time), most of these formats will simply not be
    supportable.

VALID TIME FORMATS
    There are several categories of time formats supported by Date::Manip. These are strings which
    specify only the hour/minute/second fields.

    ISO 8601 times
        A time may be also be complete or truncated. Again, Date::Manip treats some formats as
        complete even though the specification calls them truncated.

        A time may include the following fields:

           HH    2-digit representation of the hour
           MN    2-digit representation of the minutes
           SS    2-digit representation of the seconds
           H+    1+ digit representation of fractional hours
           M+    1+ digit representation of fractional minutes
           S+    1+ digit representation of fractional seconds

        The following time formats are considered complete by Date::Manip. The time 12:30:15 will be
        expressed in the examples.

           Format      Notes   Examples

           HHMNSS      2       123015

           HH:MN:SS            12:30:15

           HHMNSS,S+           123015,5
           HH:MN:SS,S+         12:30:15,5
                               Fractional seconds are ignored

           HHMN,M+             1230,25
           HH:MN,M+            12:30,25
                               This is 12:30:00 + 0.25 minutes

           HH,H+               12,5
                               This is 12:00:00 + 0.5 hours, so
                               this is equivalent to 12:30:00

           -MNSS       1       -3015
           -MN:SS              -30:15

           --SS        1       --15

           -MNSS,S+    1       -3015,5
           -MN:SS,S+           -30:15,5

           -MN,M+      1       -30,25

           --SS,S+     1       --15,5

           HHMN        3       1230
           HH:MN               12:30

        The following time formats are truncated:

           HH                  12

           -MN                 -30

        Notes:

        1 These formats are considered truncated in the standard, but since they do include (or
        imply, using the current time for defaults) all of the fields, and since they do not
        introduce any parsing complexities, the standard is relaxed, and they are treated as
        complete.

        2 The HHMNSS format will not be correctly parsed since it is impossible to distinguish
        between it and YYMMDD. In order to parse an all-digit time, add the string ",0" to the end
        to force it to be interpreted as a time or include time zone information (either a zone name
        or abbreviation... an offset will not work in this case).

        3 The HH:MN format will be treated as complete, even though it is incomplete due to missing
        the seconds. In real life, expressing a time in the HH:MN format is very common, and is
        regarded as complete, and might include time zone information.

        ISO 8601 times may be followed by a time zone unless they are truncated. Truncated times may
        not include a timezone. Date::Manip relaxes the constraints placed on the time zone format
        and allows any of the methods used to specify the time zone including time zone name,
        abbreviation, or offset. The time zone may be separated from the time by a space, but it is
        not required.

        Another constraint that is relaxed is that the fractional part may be specified using a
        period. In other words, the following are equivalent:

           12:30,25
           12:30.25

        It should be noted (as it is in the specification) that using a negative time zone offset
        may cause confusion. In addition to visually confusing, it may not be parsed correctly. For
        example, the time:

           123005-0300

        may not be parsed correctly. When using an offset time zone, you should always use the colon
        separators in the time:

           12:30:05-0300

    Other time formats
        A time may include any of the following fields:

           H24   1- or 2-digit representation of the hour (0-23)
           H12   1- or 2-digit representation of the hour (1-12)
           MN    2-digit representation of the minutes
           SS    2-digit representation of the seconds
           H+    1+ digit representation of fractional hours
           M+    1+ digit representation of fractional minutes
           S+    1+ digit representation of fractional seconds
           AM    A language specific AM/PM string

        The following time formats are accepted:

           Format              Examples

           H24:MN:SS           17:30:15
           H12:MN:SS AM        5:30:15 PM
           H12:MN:SS

           H24:MN:SS,S+        17:30:15,5
           H12:MN:SS,S+ AM     5:30:15,5 PM
           H12:MN:SS,S+        Fractional seconds are ignored

           H24:MN,M+           17:30,25
           H12:MN,M+ AM        5:30,25 PM
           H12:MN,M+           This is 17:30:00 + 0.25 minutes

           H24,H+              17,5
           H12,H+ AM           5,5 PM
           H12,H+              This is 17:00:00 + 0.5 hours, so
                               this is equivalent to 17:30:00

           H24:MN              17:30
           H12:MN AM           5:30 PM
           H12:MN

           H12 AM              5 PM

        The fractional part may be specified using a comma or a period. Fractional seconds may also
        be separated using a colon. A language specific fractional separator may also be available
        for some languages.

        In other words, the following are equivalent:

           12:30:20,25
           12:30:20.25
           12:30:20:25

        Some languages have alternate H:MN and MN:S separators. For example, one H:MN separator in
        French is 'h' (the MN:S separator is still a colon), so the following are equivalent:

           12:30:00
           12h30:00

        Time zone information can be included immediately following the time. It can be separated by
        whitespace from the time, or it can be immediately adjacent.

    Special time strings
        Different languages may have some words which can be used to specify a certain time of day.
        In English, for example, the following words are equivalent to the time listed:

           noon        12:00:00
           midnight    00:00:00

        So, the following are equivalent:

           Jan 2 2009 at noon
           Jan 2 2009 12:00:00

        There were two possible ways to interpret midnight. One was at the start of the day
        (00:00:00) and the other was at the end of the day (24:00:00 which would actually mean at
        00:00:00 of the following day). The first has been used to maintain backwards compatibility
        with Date::Manip 5.xx .

        Other languages have similar strings.

    In most languages, a word similar to "at" may precede the time (this does NOT apply to ISO 8601
    time formats). This word (which must be separate from all other parts of the date with
    whitespace) is optional, and the following are equivalent:

       12:30
       at 12:30

    The times "12:00 am", "12:00 pm", and "midnight" are not well defined. Date::Manip uses the
    following convention:

      midnight = 12:00am = 00:00:00
      noon     = 12:00pm = 12:00:00

    and the day goes from 00:00:00 to 23:59:59. In other words, midnight is the beginning of a day
    rather than the end of one. The time 24:00:00 is also allowed (though it is automatically
    transformed to 00:00:00 of the following day). This gives the unusual result of parsing:

      Wed Feb 8 2006 24:00:00

    which gives the date of:

      Thu Feb 9 2006 00:00:00

VALID COMBINED DATE AND TIME FORMATS
    There are several categories of strings which specify both the date and time. These include the
    following:

    ISO 8601 combined date and time
        A combined ISO 8601 date and time is a string containing a complete ISO 8601 date and a
        complete or truncated ISO 8601 time. It may also include a timezone, provided a complete
        time is included.

        Date::Manip relaxes the restrictions on how the two are combined. The time may be separated
        from the date by space, dash, or the letter T, or the two may be joined with nothing
        separating them.

        When the time immediately follows the date, or when the two are separated by a dash, the
        resulting string MUST be unambiguous. Provided the date includes all of the dashes in it
        (i.e. YY-MM-DD instead of YYMMDD), it is rare that there is any ambiguity. If the date does
        not include dashes, the strings may be ambiguous, and in this case, separating the date and
        time with a space or the letter T is useful (and perhaps necessary) to correctly interpret
        the string.

        The DoY formats should always be separated from the time by something. They are visually
        confusing if they are not separated from the time.

        Time zone information can be included immediately following a complete time. It may not be
        included if no time is given, or if a truncated time is included. The time zone may be
        separated from the time with whitespace, or it can be immediately adjacent to it (since the
        ISO 8601 specification allows it in some cases).

    Non-ISO 8601 combined date and time
        A date from any of the non-ISO 8601 formats above may be combined with any of the non-ISO
        8601 time formats above in any combination to form a valid combined date and time.

    Deltas
        Dates are often specified in terms of a delta from "now". For example, "in 2 days".

        Most valid deltas can be used to specify a date, and the date is defined as that delta added
        to "now". Refer to the Date::Manip::Delta documentation for a list of valid delta formats.

        If the delta itself does not include a time part, the time may be specified explicitly. For
        example:

           in 3 days at 12:00:00
           in 3 days at 12:00:00 PST

        will take the delta part "in 3 days" and add it to the current time, then set the time to
        12:00:00.

        It is NOT allowed to include an explicit time if any time segment was included in the delta.
        For example, the following is invalid:

           in 3 days 2 hours at 12:00:00

        One additional format that is supported is to include only week (or higher) components in
        the delta and to set the day of week. For example:

          Friday in 2 weeks
          in 2 weeks on Friday
          Friday 2 weeks ago
          2 weeks ago on Friday at 13:45

        These first apply the delta (of weeks, months, and years) to the current time, and then set
        the day to the given day-of-week in that week.

    Special date and time strings
        Most language have strings which can be used to specify the full date and time (relative to
        the current date and time). In English, these include the string:

           now

        They may also have a timezone attached:

           now PST

    Additional combined date and time formats
        The following formats are also supported:

           epoch SECS
              The number of seconds since the epoch
              (Jan 1, 1970 00:00:00 GMT). SECS may
              be negative to give time before the
              epoch.

        or

           epoch SECS TIMEZONE

    A couple of notes:

    Commas may be included in all date formats arbitrarily (except for ISO 8601 formats where they
    may only be included when allowed by the specification).

    The time/time zone is removed from the date before the date is parsed, so the time may appear
    before or after the date, or between any two parts of the date.

    The time and the zone do not need to be adjacent, so the string:

       Jan 21 17:13:27 2010 -0400

    will work. If the timezone is separate from the date, it MUST be separated from any other
    portion of the date by whitespace.

    Certain words such as "on", "in", "at", "of", etc. which commonly appear in a date or time are
    ignored (except in ISO 8601 formats).

PRINTF DIRECTIVES
    The following printf directives are replaced with information from the date.

       Year
           %y     year                     - 00 to 99
           %Y     year                     - 0001 to 9999

       Month, Week
           %m     month of year            - 01 to 12
           %f     month of year            - " 1" to "12"
           %b,%h  month abbreviation       - Jan to Dec
           %B     month name               - January to December

       Day
           %j     day of the year          - 001 to 366
           %d     day of month             - 01 to 31
           %e     day of month             - " 1" to "31"
           %v     weekday abbreviation     - " S"," M"," T", ...
           %a     weekday abbreviation     - Sun to Sat
           %A     weekday name             - Sunday to Saturday
           %w     day of week              - 1 to 7 (1=Monday)
           %E     day of month with
                  suffix                   - 1st, 2nd, 3rd...

       Hour
           %H     hour                     - 00 to 23
           %k     hour                     - " 0" to "23"
           %i     hour                     - " 1" to "12"
           %I     hour                     - 01 to 12
           %p     AM or PM

       Minute, Second, Time zone
           %M     minute                   - 00 to 59
           %S     second                   - 00 to 59
           %Z     time zone abbreviation   - EDT
           %z     time zone as GMT offset  - +0100 (see Note 4)
           %N     time zone as GMT offset  - +01:00:00

       Epoch (see NOTE 3 below)
           %s     seconds from
                  1/1/1970 GMT             - negative if before
           %o     seconds from 1/1/1970
                  in the current time
                  zone

       Date, Time
           %c     %a %b %e %H:%M:%S %Y     - Fri Apr 28 17:23:15 1995
           %C,%u  %a %b %e %H:%M:%S %Z %Y  - Fri Apr 28 17:25:57 EDT 1995
           %g     %a, %d %b %Y %H:%M:%S %Z - Fri, 28 Apr 1995 17:23:15 EDT
           %D     %m/%d/%y                 - 04/28/95
           %x     %m/%d/%y or %d/%m/%y     - 04/28/95 or 28/04/95
                                             (Depends on DateFormat variable)
           %l     date in ls(1) format (see NOTE 1 below)
                    %b %e %H:%M            - Apr 28 17:23 (*)
                    %b %e  %Y              - Apr 28  1993 (*)
           %r     %I:%M:%S %p              - 05:39:55 PM
           %R     %H:%M                    - 17:40
           %T,%X  %H:%M:%S                 - 17:40:58
           %V     %m%d%H%M%y               - 0428174095
           %Q     %Y%m%d                   - 19961025
           %q     %Y%m%d%H%M%S             - 19961025174058
           %P     %Y%m%d%H:%M:%S           - 1996102517:40:58
           %O     %Y-%m-%dT%H:%M:%S        - 1996-10-25T17:40:58
           %F     %A, %B %e, %Y            - Sunday, January  1, 1996
           %K     %Y-%j                    - 1997-045

       Special Year/Week formats (see NOTE 2 below)
           %G     year, Monday as first
                  day of week              - 0001 to 9999
           %W     week of year, Monday
                  as first day of week     - 01 to 53
           %L     year, Sunday as first
                  day of week              - 0001 to 9999
           %U     week of year, Sunday
                  as first day of week     - 01 to 53
           %J     %G-W%W-%w                - 1997-W02-2

       Other formats
           %n     insert a newline character
           %t     insert a tab character
           %%     insert a `%' character
           %+     insert a `+' character

       All other characters are currently unused, but may be used in the
       future.  They currently insert the character following the %.

       The following multi-character formats also exist:

       Extended formats
           %<A=NUM>   These returns the NUMth value of the %A, %a, and %v formats
           %<a=NUM>   respectively.  In English, that would yield:
           %<v=NUM>      %<A=2>   => Tuesday
                         %<a=2>   => Tue
                         %<v=2>   => T
                      NUM must be in the range 1-7.

           %<B=NUM>   These return the NUMth value of the %B and %b formats
           %<b=NUM>   respectively.  In English, that would yield:
                         %<B=2>   => February
                         %<b=2>   => Feb
                      NUM must be in the range 1-12 (or 01-12).

           %<p=NUM>   These return the NUMth value of the %p format.  In
                      English, that would yield:
                         %<p=1>   => AM
                         %<p=2>   => PM
                      NUM must be in the range 1-2.

           %<E=NUM>   These return the NUMth value of the %E format.  In
                      English, that would yield:
                         %<E=1>   => 1st
                         %<E=53>  => 53rd
                      NUM must be in the range 1-53.

    If a lone percent is the final character in a format, it is ignored.

    The formats used in this routine were originally based on date.pl (version 3.2) by Terry
    McGonigal, as well as a couple taken from different versions of the Solaris date(1) command.
    Also, several have been added which are unique to Date::Manip.

    NOTE 1:

    The ls format (%l) applies to date within the past OR future 6 months! Any date that is before
    the date NOW - 6 months, or that is on or after the date NOW + 6 months will have the year
    printed out.

    The later time must be on or after so that there is no ambiguity. If it is now
    2000-06-06-12:00:00, then the date 1999-12-06-12:00:00 will be written as "Dec 6 12:00" but the
    date 2000-12-06-12:00:00 will be written as "Dec 6 2000".

    NOTE 2:

    The %U, %W, %L, %G, and %J formats are used to support the ISO-8601 format: YYYY-wWW-D. In this
    format, a date is written as a year, the week of the year, and the day of the week. Technically,
    the week may be considered to start on any day of the week, but Sunday and Monday are the both
    common choices, so both are supported.

    The %W and %G formats return the week-of-year and the year treating weeks as starting on Monday.

    The %U and %L formats return the week-of-year and the year treating weeks as starting on Sunday.

    Most of the time, the %L and %G formats returns the same value as the %Y format, but there is a
    problem with days occurring in the first or last week of the year.

    The ISO-8601 representation of Jan 1, 1993 written in the YYYY-wWW-D format is actually
    1992-W53-5. In other words, Jan 1 is treated as being in the last week of the preceding year.
    Depending on the year, days in the first week of a year may belong to the previous year, and
    days in the final week of a year may belong to the next year. The week is assigned to the year
    which has most of the days. For example, if the week starts on Sunday, then the last week of
    2003 is 2003-12-28 to 2004-01-03. This week is assigned to 2003 since 4 of the days in it are in
    2003 and only 3 of them are in 2004. The first week of 2004 starts on 2004-01-04.

    The %U and %W formats return a week-of-year number from 01 to 53. %L and %G return the
    corresponding year, and to get this type of information, you should always use the (%W,%G)
    combination or (%U,%L) combination. %Y should not be used as it will yield incorrect results.

    %J returns the full ISO-8601 format (%G-W%W-%w).

    NOTE 3:

    The %s and %o formats return negative values if the date is before the start of the epoch. Other
    Unix utilities would return an error, or a zero, so if you are going to use Date::Manip in
    conjunction with these, be sure to check for a negative value.

    NOTE 4:

    The %z format returns the offset in the RFC 822 specified format +0500 . Most offsets are full
    hour amounts, so this is not a problem, but some offsets are irregular (+05:17:30). In this
    case, the string returned is +051730 which isn't RFC 822 compliant, but since RFC 822 ignores
    this situation, I had to decide between returning an incorrect value, or breaking strict
    compliance, and I chose the second option.

KNOWN BUGS
    None known.

BUGS AND QUESTIONS
    Please refer to the Date::Manip::Problems documentation for information on submitting bug
    reports or questions to the author.

SEE ALSO
    Date::Manip - main module documentation

LICENSE
    This script is free software; you can redistribute it and/or modify it under the same terms as
    Perl itself.

AUTHOR
    Sullivan Beck (sbeck AT cpan.org)

Date::Manip::Date(3pm)
NAME SYNOPSIS DESCRIPTION METHODS ISSUES WITH PARSING DATES VALID TIME ZONE FORMATS VALID DATE FORMATS A NOTE ABOUT FOREIGN LANGUAGE DATES VALID TIME FORMATS VALID COMBINED DATE AND TIME FORMATS PRINTF DIRECTIVES KNOWN BUGS BUGS AND QUESTIONS SEE ALSO LICENSE AUTHOR

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