# Log::Log4perl::DateFormat - phpMan

## NAME
    [Log::Log4perl::DateFormat] - Log4perl advanced date formatter helper
    class

## SYNOPSIS
          # Either in a log4j.conf file ...
        log4perl.appender.Logfile.layout = \
            [Log::Log4perl::Layout::PatternLayout]
        log4perl.appender.Logfile.layout.ConversionPattern = %d{MM/dd HH:mm} %m

          # ... or via the PatternLayout class ...
        use [Log::Log4perl::Layout::PatternLayout];
        my $layout = [Log::Log4perl::Layout::PatternLayout]->new(
            "%d{HH:mm:ss,SSS} %m");

          # ... or even directly with this helper class:
        use [Log::Log4perl::DateFormat];
        my $format = [Log::Log4perl::DateFormat]->new("HH:mm:ss,SSS");
        my $time = time();
        print $format->format($time), "\n";
            # => "17:02:39,000"

## DESCRIPTION
    "[Log::Log4perl::DateFormat]" is a helper class for the advanced date
    formatting functions in "[Log::Log4perl::Layout::PatternLayout]", and
    adheres (mostly) to the log4j SimpleDateFormat spec available on

        <http://download.oracle.com/javase/1.4.2/docs/api/java/text/SimpleDateFormat.html>

    It supports the following placeholders:

        Symbol Meaning              Presentation    Example
        ------ -------              ------------    -------
        G      era designator       (Text)          AD
        e      epoch seconds        (Number)        1315011604
        y      year                 (Number)        1996
        M      month in year        (Text & Number) July & 07
        d      day in month         (Number)        10
        h      hour in am/pm (1~12) (Number)        12
        H      hour in day (0~23)   (Number)        0
        m      minute in hour       (Number)        30
        s      second in minute     (Number)        55
        S      millisecond          (Number)        978
        E      day in week          (Text)          Tuesday
        D      day in year          (Number)        189
        F      day of week in month (Number)        2 (2nd Wed in July)
        w      week in year         (Number)        27
        W      week in month        (Number)        2
        a      am/pm marker         (Text)          PM
        k      hour in day (1~24)   (Number)        24
        K      hour in am/pm (0~11) (Number)        0
        z      time zone            (Text)          Pacific Standard Time
        Z      RFC 822 time zone    (Text)          -0800
        '      escape for text      (Delimiter)
        ''     single quote         (Literal)       '

        Presentation explanation:

        (Text): 4 or more pattern letters--use full form, < 4--use short or
                abbreviated form if one exists.

        (Number): the minimum number of digits. Shorter numbers are
                  zero-padded to this amount. Year is handled
                  specially; that is, if the count of 'y' is 2, the
                  Year will be truncated to 2 digits.

        (Text & Number): 3 or over, use text, otherwise use number.

    For example, if you want to format the current Unix time in "MM/dd
    HH:mm" format, all you have to do is specify it in the %d{...} section
    of the PatternLayout in a Log4perl configuration file:

        # log4j.conf
        # ...
        log4perl.appender.Logfile.layout = \
            [Log::Log4perl::Layout::PatternLayout]
        log4perl.appender.Logfile.layout.ConversionPattern = %d{MM/dd HH:mm} %m

    Same goes for Perl code defining a PatternLayout for Log4perl:

        use [Log::Log4perl::Layout::PatternLayout];
        my $layout = [Log::Log4perl::Layout::PatternLayout]->new(
            "%d{MM/dd HH:mm} %m");

    Or, on a lower level, you can use the class directly:

        use [Log::Log4perl::DateFormat];
        my $format = [Log::Log4perl::DateFormat]->new("MM/dd HH:mm");
        my $time = time();
        print $format->format($time), "\n";

    While the "new()" method is expensive, because it parses the format
    strings and sets up all kinds of structures behind the scenes, followup
    calls to "format()" are fast, because "DateFormat" will just call
    "localtime()" and "sprintf()" once to return the formatted date/time
    string.

    So, typically, you would initialize the formatter once and then reuse it
    over and over again to display all kinds of time values.

    Also, for your convenience, the following predefined formats are
    available, just as outlined in the log4j spec:

        Format   Equivalent                     Example
        ABSOLUTE "HH:mm:ss,SSS"                 "15:49:37,459"
        DATE     "dd MMM yyyy HH:mm:ss,SSS"     "06 Nov 1994 15:49:37,459"
        ISO8601  "yyyy-MM-dd HH:mm:ss,SSS"      "1999-11-27 15:49:37,459"
        APACHE   "[EEE MMM dd HH:mm:ss yyyy]"   "[Wed Mar 16 15:49:37 2005]"

    So, instead of passing

        [Log::Log4perl::DateFormat]->new("HH:mm:ss,SSS");

    you could just as well say

        [Log::Log4perl::DateFormat]->new("ABSOLUTE");

    and get the same result later on.

  Known Shortcomings
    The following placeholders are currently *not* recognized, unless
    someone (and that could be you :) implements them:

        F day of week in month
        w week in year
        W week in month
        k hour in day
        K hour in am/pm
        z timezone (but we got 'Z' for the numeric time zone value)

    Also, "[Log::Log4perl::DateFormat]" just knows about English week and
    month names, internationalization support has to be added.

Millisecond Times
    More granular timestamps down to the millisecond are also supported,
    just provide the millsecond count as a second argument:

        # Advanced time, resoluion in milliseconds
        use [Time::HiRes];
        my ($secs, $msecs) = [Time::HiRes::gettimeofday]();
        print $format->format($secs, $msecs), "\n";
            # => "17:02:39,959"

## LICENSE
    Copyright 2002-2016 by Mike Schilli <<m@perlmeister.com>> and Kevin Goess
    <<cpan@goess.org>>.

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

## AUTHOR
    Please contribute patches to the project on Github:

        <http://github.com/mschilli/log4perl>

    Send bug reports or requests for enhancements to the authors via our

    MAILING LIST (questions, bug reports, suggestions/patches):
    <log4perl-devel@lists.sourceforge.net>

    Authors (please contact them via the list above, not directly): Mike
    Schilli <<m@perlmeister.com>>, Kevin Goess <<cpan@goess.org>>

    Contributors (in alphabetical order): Ateeq Altaf, Cory Bennett, Jens
    Berthold, Jeremy Bopp, Hutton Davidson, Chris R. Donnelly, Matisse
    Enzer, Hugh Esco, Anthony Foiani, James FitzGibbon, Carl Franks, Dennis
    Gregorovic, Andy Grundman, Paul Harrington, Alexander Hartmaier David
    Hull, Robert Jacobson, Jason Kohles, Jeff Macdonald, Markus Peter, Brett
    Rann, Peter Rabbitson, Erik Selberg, Aaron Straup Cope, Lars Thegler,
    David Viner, Mac Yang.

