# phpman > perldoc > Date::Manip::Obj

## NAME
    [Date::Manip::Obj](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3AObj/markdown) - Base class for [Date::Manip](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip/markdown) objects

## SYNOPSIS
    The [Date::Manip::Obj](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3AObj/markdown) class is the base class used for the following [Date::Manip](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip/markdown) classes:

    [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown)
    [Date::Manip::TZ](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ATZ/markdown)
    [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown)
    [Date::Manip::Delta](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADelta/markdown)
    [Date::Manip::Recur](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ARecur/markdown)

    This module is not intended to be called directly and performs no useful function by itself.
    Instead, use the various derived classes which inherit from it.

## DESCRIPTION
    This module contains a set of methods used by all [Date::Manip](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip/markdown) classes listed above.

    You should be familiar with the [Date::Manip::Objects](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3AObjects/markdown) and [Date::Manip::Config](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3AConfig/markdown) documentation.

    In the method descriptions below, [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown) objects will usually be used as examples,
    but (unless otherwise stated), all of the classes listed above have the same methods, and work
    in the same fashion.

## METHODS FOR CREATING OBJECTS
    In the examples below, any variable named some variation of $date ($date, $date1, $date2, ...)
    is a [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown) object. Similarly, $delta, $recur, $tz, and $base refer to objects in the
    appropriate class.

    Any $obj variable refers to an object in any of the classes.

    new There are two ways to use the new method. They are:

           $obj2  = new CLASS ($obj1,$string,@parse_opts,\@opts);
           $obj2  = $obj1->new($string,@parse_opts,\@opts)

        In both cases, all arguments are optional.

        Both methods are used to create a new object of a given class. In the first case, CLASS is
        the class of the new object. For example:

           $date  = new [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown);
           $delta = new [Date::Manip::Delta](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADelta/markdown);

        In the second method, the class of the new object will be derived from the first object. For
        example:

           $date1 = new [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown);
           $date2 = $date1->new();

        the class of the second object ($date2) is [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown) because that is the class of
        the object ($date1) used to create it.

        In both first method (when a $obj1 is passed in) and always in the second method, the new
        object will share as much information from the old object ($obj1) as possible.

        For example, if you call either of these:

           $date2 = new [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown) $date1;
           $date2 = $date1->new();

        the new date object will use the same embedded [Date::Manip::TZ](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ATZ/markdown) and [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown)
        objects.

        When specifying CLASS and including an old object, objects do not need to be of the same
        class. For example, the following are all valid:

           $date = new [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown) $delta;
           $date = new [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown) $tz;

        You can even do:

           $date = new [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown) $base;

        but this will have to create a completely new [Date::Manip::TZ](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ATZ/markdown) object, which means that
        optimal performance may not be achieved if a [Date::Manip::TZ](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ATZ/markdown) object already exists.

        There are two special cases. Either of the following will create a new [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown)
        object for handling multiple configurations:

           $base2 = new [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown) $base1;
           $base2 = $base1->new();

        Either of the following will create a new [Date::Manip::TZ](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ATZ/markdown) object with the same
        [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown) object embedded in it:

           $tz2   = new [Date::Manip::TZ](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ATZ/markdown) $tz1;
           $tz2   = $tz1->new();

        The new base object will initially have the same configuration as the original base object,
        but changing it's configuration will not affect the original base object.

        If the "\@opts" argument is passed in, it is a list reference containing a list suitable for
        passing to the config method (described below). In this case, a new [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown) object
        (and perhaps [Date::Manip::TZ](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ATZ/markdown) object) will be created. The new Base object will start as
        identical to the original one (if a previously defined object was used to create the new
        object) with the additional options in @opts added.

        In other words, the following are equivalent:

           $date  = new [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown) $obj,\@opts;

           $base  = $obj->base();
           $base2 = $base->new();
           $date = new [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown) $base2;
           $date->config(@opts);

        It should be noted that the options are applied to the NEW [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown) object, not the
        old one.

        An optional string ($string and parse opts @parse_opts) may be passed in only when creating
        a [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown), [Date::Manip::Delta](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADelta/markdown), or [Date::Manip::Recur](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ARecur/markdown) object. If passed in when
        creating a [Date::Manip::TZ](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ATZ/markdown) or [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown) object, a warning will be issued, but
        execution will continue.

        If the string is included, it will be parsed to give an initial value to the object. This
        will only be done AFTER any options are handled, so the following are equivalent:

           $date = new [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown) $string,@parse_opts,\@opts;

           $date = new [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown);
           $date->config(@opts);
           $date->parse($string,@parse_opts);

        Once a [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown) object (or any object in any other [Date::Manip](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip/markdown) class) is created,
        it should always be used to create additional objects in order to preserve cached data for
        optimal performance and memory usage.

        The one caveat is if you are working with multiple configurations as described in the
        [Date::Manip::Objects](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3AObjects/markdown) document. In that case, you may need to create completely new objects
        to allow multiple [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown) objects to be used.

    new_config
           $obj2 = $obj1->new_config($string,\@opts);

        This creates a new instance with a new [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown) object (and possibly a new
        [Date::Manip::TZ](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ATZ/markdown) object).

        For example,

           $date2 = $date1->new_config();

        creates a new [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown) object with a new [Date::Manip::TZ](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ATZ/markdown) (and [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown))
        object. Initially, it is the same configuration as the original object.

        If the object is a [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown) object, the following are equivalent:

           $base2 = $base1->new_config();

           $base2 = $base1->new();

        Both $string and "\@opts" are optional. They are used in the same way they are used in the
        new method.

    new_date
    new_delta
    new_recur
        These are shortcuts for specifying the class. The following sets of calls are all
        equivalent:

           $date  = $obj->new_date();
           $date  = new [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown)($obj);

           $delta = $obj->new_delta();
           $delta = new [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown)($obj);

        These methods all allow optional "($string,\@opts)" arguments.

## OTHER METHODS
    base
    tz
           $base = $obj->base();

        This returns the [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown) object associated with the given object.

        If $obj is a [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown) object, nothing is returned (i.e. it doesn't create a new
        copy of the object).

           $tz = $obj->tz();

        This returns the [Date::Manip::TZ](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ATZ/markdown) object associated with the given object. If $obj is a
        [Date::Manip::TZ](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ATZ/markdown) or [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown) object, nothing is returned.

    config
           $obj->config($var1,$val1,$var2,$val2,...);

        This will set the value of any configuration variables. Please refer to the
        [Date::Manip::Config](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3AConfig/markdown) manual for a list of all configuration variables and their description.

    get_config
           @var = $obj->get_config();
           $val = $obj->get_config($var1);
           @val = $obj->get_config($var1,$var2,...);

        This queries the current config values. With no argument, it will return the list of config
        variables (all lowercase).

        With one or more arguments, it returns the current values for the config variables passed in
        (case insensitive).

    err
           $err = $obj->err();

        This will return the full error message if the previous operation failed for any reason.

           $obj->[err(1)](https://www.chedong.com/phpMan.php/man/err/1/markdown);

        will clear the error code.

    is_date
    is_delta
    is_recur
           $flag = $obj->is_date();

        Returns 0 or 1, depending on the object. For example, a [Date::Manip::Date](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ADate/markdown) object returns 1
        with the is_date method, and 0 for the other two.

    version
           $vers = $obj->version($flag);

        This returns the version of [Date::Manip](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip/markdown).

        If $flag is passed in, and $obj is not a [Date::Manip::Base](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3ABase/markdown) object, the version and timezone
        information will be passed back.

## KNOWN BUGS
    None known.

## BUGS AND QUESTIONS
    Please refer to the [Date::Manip::Problems](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip%3A%3AProblems/markdown) documentation for information on submitting bug
    reports or questions to the author.

## SEE ALSO
    [Date::Manip](https://www.chedong.com/phpMan.php/perldoc/Date%3A%3AManip/markdown) - 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@cpan.org>)