NAME
    DateTimeX::Immutable - An immutable subclass of DateTime

VERSION
    version 0.36

SYNOPSIS
        use DateTimeX::Immutable;
        my $now = DateTimeX::Immutable->now;  # 2012-12-12T11:15:10
        my $day = $now->with_hour( 0 )->with_minute( 0 )->with_second( 0 );
        say $now;           # 2012-12-12T11:15:10
        say $day;           # 2012-12-12T00:00:00
        $now->set_day( 1 ); # throws an exception

    or with aliased:

        use aliased 'DateTimeX::Immutable' => 'DateTime';
        my $now = DateTime->now;  # 2012-12-12T11:15:10
        my $day = $now->with_hour( 0 )->with_minute( 0 )->with_second( 0 );
        say $now;           # 2012-12-12T11:15:10
        say $day;           # 2012-12-12T00:00:00
        $now->set_day( 1 ); # throws an exception

DESCRIPTION
    This is subclass of DateTime which throws an exception when methods that
    modify the object are called. Those methods are replaced with new
    methods that leave the original object untouched, and return a new
    "DateTimeX::Immutable" object with the expected changes.

    The following methods now thrown an exception:

        $dt->add_duration()
        $dt->subtract_duration()
        $dt->add()
        $dt->subtract()
        $dt->set()
        $dt->set_year()
        $dt->set_month()
        $dt->set_day()
        $dt->set_hour()
        $dt->set_minute()
        $dt->set_second()
        $dt->set_nanosecond()
        $dt->truncate()

    and are replaced by these methods which return the changed value:

        $dt->plus_duration()
        $dt->minus_duration()
        $dt->plus()
        $dt->minus()
        $dt->with_component()
        $dt->with_year()
        $dt->with_month()
        $dt->with_day()
        $dt->with_hour()
        $dt->with_minute()
        $dt->with_second()
        $dt->with_nanosecond()
        $dt->trunc()

    At the moment, "set_time_zone", "set_locale", and "set_formatter"
    continue to act as mutators. DateTime uses these internally and changing
    them creates unexpected behavior. These methods also do not really
    change the time value.

    See DateTime for the rest of the documentation.

WHY
    Reasons why this module eixsts:

    Mutability is bad!
    DateTime::Moonpig: Great idea but changes too much. We still want to be
    to truncate, set_*, etc, we just want the result returned. Changing the
    math goes beyond the scope of our needs. No integration with DBIC.
    Time::Moment: Excellent, but for code that already uses DateTime we want
    to continue. Also, Time::Moment's plugin for DBIC doesn't support native
    db date formats.

    (TODO: Expand on explanation for this module's existence.)

SEE ALSO
    DateTime, DateTime::Moonpig, Time::Moment

AUTHOR
    Mark Grimes, <mgrimes@cpan.org>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2015 by Mark Grimes, <mgrimes@cpan.org>.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.