This file is indexed.

/usr/share/perl5/DateTime/TimeZone.pm is in libdatetime-timezone-perl 1:2.09-1+2018i.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
package DateTime::TimeZone;

use 5.008004;

use strict;
use warnings;
use namespace::autoclean;

our $VERSION = '2.09';

use DateTime::TimeZone::Catalog;
use DateTime::TimeZone::Floating;
use DateTime::TimeZone::Local;
use DateTime::TimeZone::OffsetOnly;
use DateTime::TimeZone::OlsonDB::Change;
use DateTime::TimeZone::UTC;
use Module::Runtime qw( require_module );
use Params::ValidationCompiler 0.13 qw( validation_for );
use Specio::Library::Builtins;
use Specio::Library::String;
use Try::Tiny;

## no critic (ValuesAndExpressions::ProhibitConstantPragma)
use constant INFINITY => 100**1000;
use constant NEG_INFINITY => -1 * ( 100**1000 );

# the offsets for each span element
use constant UTC_START   => 0;
use constant UTC_END     => 1;
use constant LOCAL_START => 2;
use constant LOCAL_END   => 3;
use constant OFFSET      => 4;
use constant IS_DST      => 5;
use constant SHORT_NAME  => 6;

my %SpecialName = map { $_ => 1 }
    qw( EST MST HST CET EET MET WET EST5EDT CST6CDT MST7MDT PST8PDT );

{
    my $validator = validation_for(
        name             => '_check_new_params',
        name_is_optional => 1,
        params           => {
            name => {
                type => t('NonEmptyStr'),
            },
        },
    );

    sub new {
        shift;
        my %p = $validator->(@_);

        if ( exists $DateTime::TimeZone::Catalog::LINKS{ $p{name} } ) {
            $p{name} = $DateTime::TimeZone::Catalog::LINKS{ $p{name} };
        }
        elsif ( exists $DateTime::TimeZone::Catalog::LINKS{ uc $p{name} } ) {
            $p{name} = $DateTime::TimeZone::Catalog::LINKS{ uc $p{name} };
        }

        unless ( $p{name} =~ m{/}
            || $SpecialName{ $p{name} } ) {
            if ( $p{name} eq 'floating' ) {
                return DateTime::TimeZone::Floating->instance;
            }

            if ( $p{name} eq 'local' ) {
                return DateTime::TimeZone::Local->TimeZone();
            }

            if ( $p{name} eq 'UTC' || $p{name} eq 'Z' ) {
                return DateTime::TimeZone::UTC->instance;
            }

            return DateTime::TimeZone::OffsetOnly->new( offset => $p{name} );
        }

        my $subclass = $p{name};
        $subclass =~ s{/}{::}g;
        $subclass =~ s/-(\d)/_Minus$1/;
        $subclass =~ s/\+/_Plus/;
        $subclass =~ s/-/_/g;

        my $real_class = "DateTime::TimeZone::$subclass";

        die "The timezone '$p{name}' is an invalid name.\n"
            unless $real_class =~ /^\w+(::\w+)*$/;

        unless ( $real_class->can('instance') ) {
            ($real_class)
                = $real_class =~ m{\A([a-zA-Z0-9_]+(?:::[a-zA-Z0-9_]+)*)\z};

            my $e;
            try {
                ## no critic (Variables::RequireInitializationForLocalVars)
                local $SIG{__DIE__};
                require_module($real_class);
            }
            catch {
                $e = $_;
            };

            if ($e) {
                my $regex = join '.', split /::/, $real_class;
                $regex .= '\\.pm';

                if ( $e =~ /^Can't locate $regex/i ) {
                    die
                        "The timezone '$p{name}' could not be loaded, or is an invalid name.\n";
                }
                else {
                    die $e;
                }
            }
        }

        my $zone = $real_class->instance( name => $p{name}, is_olson => 1 );

        if ( $zone->is_olson() ) {
            my $object_version
                = $zone->can('olson_version')
                ? $zone->olson_version()
                : 'unknown';
            my $catalog_version = DateTime::TimeZone::Catalog->OlsonVersion();

            if ( $object_version ne $catalog_version ) {
                warn
                    "Loaded $real_class, which is from a different version ($object_version) of the Olson database than this installation of DateTime::TimeZone ($catalog_version).\n";
            }
        }

        return $zone;
    }
}

{
    my $validator = validation_for(
        name             => '_check_init_params',
        name_is_optional => 1,
        params           => {
            name => {
                type => t('NonEmptyStr'),
            },
            spans => {
                type => t('ArrayRef'),
            },
            is_olson => {
                type    => t('Bool'),
                default => 0,
            },
        },
    );

    ## no critic (Subroutines::ProhibitUnusedPrivateSubroutines)
    sub _init {
        my $class = shift;
        my %p     = $validator->(@_);

        my $self = bless {
            name     => $p{name},
            spans    => $p{spans},
            is_olson => $p{is_olson},
        }, $class;

        foreach my $k (qw( last_offset last_observance rules max_year )) {
            my $m = "_$k";
            $self->{$k} = $self->$m() if $self->can($m);
        }

        return $self;
    }
    ## use critic
}

sub is_olson { $_[0]->{is_olson} }

sub is_dst_for_datetime {
    my $self = shift;

    my $span = $self->_span_for_datetime( 'utc', $_[0] );

    return $span->[IS_DST];
}

sub offset_for_datetime {
    my $self = shift;

    my $span = $self->_span_for_datetime( 'utc', $_[0] );

    return $span->[OFFSET];
}

sub offset_for_local_datetime {
    my $self = shift;

    my $span = $self->_span_for_datetime( 'local', $_[0] );

    return $span->[OFFSET];
}

sub short_name_for_datetime {
    my $self = shift;

    my $span = $self->_span_for_datetime( 'utc', $_[0] );

    return $span->[SHORT_NAME];
}

sub _span_for_datetime {
    my $self = shift;
    my $type = shift;
    my $dt   = shift;

    my $method = $type . '_rd_as_seconds';

    my $end = $type eq 'utc' ? UTC_END : LOCAL_END;

    my $span;
    my $seconds = $dt->$method();
    if ( $seconds < $self->max_span->[$end] ) {
        $span = $self->_spans_binary_search( $type, $seconds );
    }
    else {
        my $until_year = $dt->utc_year + 1;
        $span = $self->_generate_spans_until_match(
            $until_year, $seconds,
            $type
        );
    }

    # This means someone gave a local time that doesn't exist
    # (like during a transition into savings time)
    unless ( defined $span ) {
        my $err = 'Invalid local time for date';
        $err .= q{ } . $dt->iso8601 if $type eq 'utc';
        $err .= ' in time zone: ' . $self->name;
        $err .= "\n";

        die $err;
    }

    return $span;
}

sub _spans_binary_search {
    my $self = shift;
    my ( $type, $seconds ) = @_;

    my ( $start, $end ) = _keys_for_type($type);

    my $min = 0;
    my $max = scalar @{ $self->{spans} } + 1;
    my $i   = int( $max / 2 );

    # special case for when there are only 2 spans
    $i++ if $max % 2 && $max != 3;

    $i = 0 if @{ $self->{spans} } == 1;

    while (1) {
        my $current = $self->{spans}[$i];

        if ( $seconds < $current->[$start] ) {
            $max = $i;
            my $c = int( ( $i - $min ) / 2 );
            $c ||= 1;

            $i -= $c;

            return if $i < $min;
        }
        elsif ( $seconds >= $current->[$end] ) {
            $min = $i;
            my $c = int( ( $max - $i ) / 2 );
            $c ||= 1;

            $i += $c;

            return if $i >= $max;
        }
        else {

            # Special case for overlapping ranges because of DST and
            # other weirdness (like Alaska's change when bought from
            # Russia by the US).  Always prefer latest span.
            if ( $current->[IS_DST] && $type eq 'local' ) {

                # Asia/Dhaka in 2009j goes into DST without any known
                # end-of-DST date (wtf, Bangladesh).
                return $current if $current->[UTC_END] == INFINITY;

                my $next = $self->{spans}[ $i + 1 ];

                # Sometimes we will get here and the span we're
                # looking at is the last that's been generated so far.
                # We need to try to generate one more or else we run
                # out.
                $next ||= $self->_generate_next_span;

                die "No next span in $self->{max_year}" unless defined $next;

                if (   ( !$next->[IS_DST] )
                    && $next->[$start] <= $seconds
                    && $seconds <= $next->[$end] ) {
                    return $next;
                }
            }

            return $current;
        }
    }
}

sub _generate_next_span {
    my $self = shift;

    my $last_idx = $#{ $self->{spans} };

    my $max_span = $self->max_span;

    # Kind of a hack, but AFAIK there are no zones where it takes
    # _more_ than a year for a _future_ time zone change to occur, so
    # by looking two years out we can ensure that we will find at
    # least one more span.  Of course, I will no doubt be proved wrong
    # and this will cause errors.
    $self->_generate_spans_until_match(
        $self->{max_year} + 2,
        $max_span->[UTC_END] + ( 366 * 86400 ), 'utc'
    );

    return $self->{spans}[ $last_idx + 1 ];
}

sub _generate_spans_until_match {
    my $self                = shift;
    my $generate_until_year = shift;
    my $seconds             = shift;
    my $type                = shift;

    my @changes;
    my @rules = @{ $self->_rules };
    foreach my $year ( $self->{max_year} .. $generate_until_year ) {
        ## no critic (ControlStructures::ProhibitCStyleForLoops)
        for ( my $x = 0; $x < @rules; $x++ ) {
            my $last_offset_from_std;

            if ( @rules == 2 ) {
                $last_offset_from_std
                    = $x
                    ? $rules[0]->offset_from_std
                    : $rules[1]->offset_from_std;
            }
            elsif ( @rules == 1 ) {
                $last_offset_from_std = $rules[0]->offset_from_std;
            }
            else {
                my $count = scalar @rules;
                die
                    "Cannot generate future changes for zone with $count infinite rules\n";
            }

            my $rule = $rules[$x];

            my $next = $rule->utc_start_datetime_for_year(
                $year,
                $self->{last_offset}, $last_offset_from_std
            );

            # don't bother with changes we've seen already
            next if $next->utc_rd_as_seconds < $self->max_span->[UTC_END];

            push @changes,
                DateTime::TimeZone::OlsonDB::Change->new(
                type                 => 'rule',
                utc_start_datetime   => $next,
                local_start_datetime => $next + DateTime::Duration->new(
                    seconds => $self->{last_observance}->total_offset
                        + $rule->offset_from_std
                ),
                short_name => $self->{last_observance}
                    ->formatted_short_name( $rule->letter ),
                observance => $self->{last_observance},
                rule       => $rule,
                );
        }
    }

    $self->{max_year} = $generate_until_year;

    my @sorted
        = sort { $a->utc_start_datetime <=> $b->utc_start_datetime } @changes;

    my ( $start, $end ) = _keys_for_type($type);

    my $match;
    ## no critic (ControlStructures::ProhibitCStyleForLoops)
    for ( my $x = 1; $x < @sorted; $x++ ) {
        my $span = DateTime::TimeZone::OlsonDB::Change::two_changes_as_span(
            @sorted[ $x - 1, $x ] );

        $span = _span_as_array($span);

        push @{ $self->{spans} }, $span;

        $match = $span
            if $seconds >= $span->[$start] && $seconds < $span->[$end];
    }

    return $match;
}

sub max_span { $_[0]->{spans}[-1] }

sub _keys_for_type {
    $_[0] eq 'utc' ? ( UTC_START, UTC_END ) : ( LOCAL_START, LOCAL_END );
}

sub _span_as_array {
    [
        @{ $_[0] }{
            qw( utc_start utc_end local_start local_end offset is_dst short_name )
        }
    ];
}

sub is_floating {0}

sub is_utc {0}

sub has_dst_changes {0}

sub name { $_[0]->{name} }
sub category { ( split /\//, $_[0]->{name}, 2 )[0] }

sub is_valid_name {
    my $class = shift;
    my $name  = shift;

    my $tz = try {
        ## no critic (Variables::RequireInitializationForLocalVars)
        local $SIG{__DIE__};
        $class->new( name => $name );
    };

    return $tz && $tz->isa('DateTime::TimeZone') ? 1 : 0;
}

sub STORABLE_freeze {
    my $self = shift;

    return $self->name;
}

sub STORABLE_thaw {
    my $self = shift;
    shift;
    my $serialized = shift;

    my $class = ref $self || $self;

    my $obj;
    if ( $class->isa(__PACKAGE__) ) {
        $obj = __PACKAGE__->new( name => $serialized );
    }
    else {
        $obj = $class->new( name => $serialized );
    }

    %$self = %$obj;

    return $self;
}

#
# Functions
#
sub offset_as_seconds {
    my $offset = shift;
    $offset = shift if try {
        ## no critic (Variables::RequireInitializationForLocalVars)
        local $SIG{__DIE__};
        $offset->isa('DateTime::TimeZone');
    };

    return undef unless defined $offset;

    return 0 if $offset eq '0';

    my ( $sign, $hours, $minutes, $seconds );
    if ( $offset =~ /^([\+\-])?(\d\d?):(\d\d)(?::(\d\d))?$/ ) {
        ( $sign, $hours, $minutes, $seconds ) = ( $1, $2, $3, $4 );
    }
    elsif ( $offset =~ /^([\+\-])?(\d\d)(\d\d)(\d\d)?$/ ) {
        ( $sign, $hours, $minutes, $seconds ) = ( $1, $2, $3, $4 );
    }
    else {
        return undef;
    }

    $sign = '+' unless defined $sign;
    return undef unless $hours >= 0   && $hours <= 99;
    return undef unless $minutes >= 0 && $minutes <= 59;
    return undef
        unless !defined($seconds) || ( $seconds >= 0 && $seconds <= 59 );

    my $total = $hours * 3600 + $minutes * 60;
    $total += $seconds if $seconds;
    $total *= -1 if $sign eq '-';

    return $total;
}

sub offset_as_string {
    my $offset = shift;
    $offset = shift if try {
        ## no critic (Variables::RequireInitializationForLocalVars)
        local $SIG{__DIE__};
        $offset->isa('DateTime::TimeZone');
    };

    return undef unless defined $offset;
    return undef unless $offset >= -359999 && $offset <= 359999;

    my $sign = $offset < 0 ? '-' : '+';

    $offset = abs($offset);

    my $hours = int( $offset / 3600 );
    $offset %= 3600;
    my $mins = int( $offset / 60 );
    $offset %= 60;
    my $secs = int($offset);

    return (
        $secs
        ? sprintf( '%s%02d%02d%02d', $sign, $hours, $mins, $secs )
        : sprintf( '%s%02d%02d',     $sign, $hours, $mins )
    );
}

# These methods all operate on data contained in the DateTime/TimeZone/Catalog.pm file.

sub all_names {
    return wantarray
        ? @DateTime::TimeZone::Catalog::ALL
        : [@DateTime::TimeZone::Catalog::ALL];
}

sub categories {
    return wantarray
        ? @DateTime::TimeZone::Catalog::CATEGORY_NAMES
        : [@DateTime::TimeZone::Catalog::CATEGORY_NAMES];
}

sub links {
    return wantarray
        ? %DateTime::TimeZone::Catalog::LINKS
        : {%DateTime::TimeZone::Catalog::LINKS};
}

sub names_in_category {
    shift if $_[0]->isa('DateTime::TimeZone');
    return unless exists $DateTime::TimeZone::Catalog::CATEGORIES{ $_[0] };

    return wantarray
        ? @{ $DateTime::TimeZone::Catalog::CATEGORIES{ $_[0] } }
        : $DateTime::TimeZone::Catalog::CATEGORIES{ $_[0] };
}

sub countries {
    wantarray
        ? ( sort keys %DateTime::TimeZone::Catalog::ZONES_BY_COUNTRY )
        : [ sort keys %DateTime::TimeZone::Catalog::ZONES_BY_COUNTRY ];
}

sub names_in_country {
    shift if $_[0]->isa('DateTime::TimeZone');

    return
        unless
        exists $DateTime::TimeZone::Catalog::ZONES_BY_COUNTRY{ lc $_[0] };

    return
        wantarray
        ? @{ $DateTime::TimeZone::Catalog::ZONES_BY_COUNTRY{ lc $_[0] } }
        : $DateTime::TimeZone::Catalog::ZONES_BY_COUNTRY{ lc $_[0] };
}

1;

# ABSTRACT: Time zone object base class and factory

__END__

=pod

=encoding UTF-8

=head1 NAME

DateTime::TimeZone - Time zone object base class and factory

=head1 VERSION

version 2.09

=head1 SYNOPSIS

  use DateTime;
  use DateTime::TimeZone;

  my $tz = DateTime::TimeZone->new( name => 'America/Chicago' );

  my $dt = DateTime->now();
  my $offset = $tz->offset_for_datetime($dt);

=head1 DESCRIPTION

This class is the base class for all time zone objects.  A time zone
is represented internally as a set of observances, each of which
describes the offset from GMT for a given time period.

Note that without the L<DateTime> module, this module does not do
much.  It's primary interface is through a L<DateTime> object, and
most users will not need to directly use C<DateTime::TimeZone>
methods.

=head2 Special Case Platforms

If you are on the Win32 platform, you will want to also install
L<DateTime::TimeZone::Local::Win32>. This will enable you to specify a time
zone of C<'local'> when creating a L<DateTime> object.

If you are on HPUX, install L<DateTime::TimeZone::HPUX>. This provides support
for HPUX style time zones like C<'MET-1METDST'>.

=head1 USAGE

This class has the following methods:

=head2 DateTime::TimeZone->new( name => $tz_name )

Given a valid time zone name, this method returns a new time zone
blessed into the appropriate subclass.  Subclasses are named for the
given time zone, so that the time zone "America/Chicago" is the
DateTime::TimeZone::America::Chicago class.

If the name given is a "link" name in the Olson database, the object
created may have a different name.  For example, there is a link from
the old "EST5EDT" name to "America/New_York".

When loading a time zone from the Olson database, the constructor
checks the version of the loaded class to make sure it matches the
version of the current DateTime::TimeZone installation. If they do not
match it will issue a warning. This is useful because time zone names
may fall out of use, but you may have an old module file installed for
that time zone.

There are also several special values that can be given as names.

If the "name" parameter is "floating", then a
C<DateTime::TimeZone::Floating> object is returned.  A floating time
zone does have I<any> offset, and is always the same time.  This is
useful for calendaring applications, which may need to specify that a
given event happens at the same I<local> time, regardless of where it
occurs.  See RFC 2445 for more details.

If the "name" parameter is "UTC", then a C<DateTime::TimeZone::UTC>
object is returned.

If the "name" is an offset string, it is converted to a number, and a
C<DateTime::TimeZone::OffsetOnly> object is returned.

=head3 The "local" time zone

If the "name" parameter is "local", then the module attempts to
determine the local time zone for the system.

The method for finding the local zone varies by operating system. See
the appropriate module for details of how we check for the local time
zone.

=over 4

=item * L<DateTime::TimeZone::Local::Unix>

=item * L<DateTime::TimeZone::Local::Win32>

=item * L<DateTime::TimeZone::Local::VMS>

=back

If a local time zone is not found, then an exception will be thrown.

=head2 $tz->offset_for_datetime( $dt )

Given a C<DateTime> object, this method returns the offset in seconds
for the given datetime.  This takes into account historical time zone
information, as well as Daylight Saving Time.  The offset is
determined by looking at the object's UTC Rata Die days and seconds.

=head2 $tz->offset_for_local_datetime( $dt )

Given a C<DateTime> object, this method returns the offset in seconds
for the given datetime.  Unlike the previous method, this method uses
the local time's Rata Die days and seconds.  This should only be done
when the corresponding UTC time is not yet known, because local times
can be ambiguous due to Daylight Saving Time rules.

=head2 $tz->is_dst_for_datetime( $dt )

Given a C<DateTime> object, this method returns true if the DateTime is
currently in Daylight Saving Time.

=head2 $tz->name

Returns the name of the time zone.

=head2 $tz->short_name_for_datetime( $dt )

Given a C<DateTime> object, this method returns the "short name" for
the current observance and rule this datetime is in.  These are names
like "EST", "GMT", etc.

It is B<strongly> recommended that you do not rely on these names for
anything other than display.  These names are not official, and many
of them are simply the invention of the Olson database maintainers.
Moreover, these names are not unique.  For example, there is an "EST"
at both -0500 and +1000/+1100.

=head2 $tz->is_floating

Returns a boolean indicating whether or not this object represents a
floating time zone, as defined by RFC 2445.

=head2 $tz->is_utc

Indicates whether or not this object represents the UTC (GMT) time
zone.

=head2 $tz->has_dst_changes

Indicates whether or not this zone has I<ever> had a change to and
from DST, either in the past or future.

=head2 $tz->is_olson

Returns true if the time zone is a named time zone from the Olson
database.

=head2 $tz->category

Returns the part of the time zone name before the first slash.  For
example, the "America/Chicago" time zone would return "America".

=head2 DateTime::TimeZone->is_valid_name($name)

Given a string, this method returns a boolean value indicating whether
or not the string is a valid time zone name.  If you are using
C<DateTime::TimeZone::Alias>, any aliases you've created will be valid.

=head2 DateTime::TimeZone->all_names

This returns a pre-sorted list of all the time zone names.  This list
does not include link names.  In scalar context, it returns an array
reference, while in list context it returns an array.

=head2 DateTime::TimeZone->categories

This returns a list of all time zone categories.  In scalar context,
it returns an array reference, while in list context it returns an
array.

=head2 DateTime::TimeZone->links

This returns a hash of all time zone links, where the keys are the
old, deprecated names, and the values are the new names.  In scalar
context, it returns a hash reference, while in list context it returns
a hash.

=head2 DateTime::TimeZone->names_in_category( $category )

Given a valid category, this method returns a list of the names in
that category, without the category portion.  So the list for the
"America" category would include the strings "Chicago",
"Kentucky/Monticello", and "New_York". In scalar context, it returns
an array reference, while in list context it returns an array.

=head2 DateTime::TimeZone->countries()

Returns a sorted list of all the valid country codes (in lower-case)
which can be passed to C<names_in_country()>. In scalar context, it
returns an array reference, while in list context it returns an array.

If you need to convert country codes to names or vice versa you can
use C<Locale::Country> to do so.

=head2 DateTime::TimeZone->names_in_country( $country_code )

Given a two-letter ISO3166 country code, this method returns a list of
time zones used in that country. The country code may be of any
case. In scalar context, it returns an array reference, while in list
context it returns an array.

This list is returned in an order vaguely based on geography and
population. In general, the least used zones come last, but there are not
guarantees of a specific order from one release to the next. This order is
probably the best option for presenting zones names to end users.

=head2 DateTime::TimeZone->offset_as_seconds( $offset )

Given an offset as a string, this returns the number of seconds
represented by the offset as a positive or negative number.  Returns
C<undef> if $offset is not in the range C<-99:59:59> to C<+99:59:59>.

The offset is expected to match either
C</^([\+\-])?(\d\d?):(\d\d)(?::(\d\d))?$/> or
C</^([\+\-])?(\d\d)(\d\d)(\d\d)?$/>.  If it doesn't match either of
these, C<undef> will be returned.

This means that if you want to specify hours as a single digit, then
each element of the offset must be separated by a colon (:).

=head2 DateTime::TimeZone->offset_as_string( $offset )

Given an offset as a number, this returns the offset as a string.
Returns C<undef> if $offset is not in the range C<-359999> to C<359999>.

=head2 Storable Hooks

This module provides freeze and thaw hooks for C<Storable> so that the
huge data structures for Olson time zones are not actually stored in
the serialized structure.

If you subclass C<DateTime::TimeZone>, you will inherit its hooks,
which may not work for your module, so please test the interaction of
your module with Storable.

=head1 DONATIONS

If you'd like to thank me for the work I've done on this module,
please consider making a "donation" to me via PayPal. I spend a lot of
free time creating free software, and would appreciate any support
you'd care to offer.

Please note that B<I am not suggesting that you must do this> in order
for me to continue working on this particular software. I will
continue to do so, inasmuch as I have in the past, for as long as it
interests me.

Similarly, a donation made in this way will probably not make me work
on this software much more, unless I get so many donations that I can
consider working on free software full time, which seems unlikely at
best.

To donate, log into PayPal and send money to autarch@urth.org or use
the button on this page:
L<http://www.urth.org/~autarch/fs-donation.html>

=head1 CREDITS

This module was inspired by Jesse Vincent's work on
Date::ICal::Timezone, and written with much help from the
datetime@perl.org list.

=head1 SEE ALSO

datetime@perl.org mailing list

http://datetime.perl.org/

The tools directory of the DateTime::TimeZone distribution includes
two scripts that may be of interest to some people.  They are
parse_olson and tests_from_zdump.  Please run them with the --help
flag to see what they can be used for.

=head1 SUPPORT

Support for this module is provided via the datetime@perl.org email list. See
http://datetime.perl.org/wiki/datetime/page/Mailing_List for details.

Please submit bugs to the CPAN RT system at
http://rt.cpan.org/NoAuth/ReportBug.html?Queue=datetime%3A%3Atimezone
or via email at bug-datetime-timezone@rt.cpan.org.

Bugs may be submitted through L<https://github.com/houseabsolute/DateTime-TimeZone/issues>.

I am also usually active on IRC as 'autarch' on C<irc://irc.perl.org>.

=head1 DONATIONS

If you'd like to thank me for the work I've done on this module, please
consider making a "donation" to me via PayPal. I spend a lot of free time
creating free software, and would appreciate any support you'd care to offer.

Please note that B<I am not suggesting that you must do this> in order for me
to continue working on this particular software. I will continue to do so,
inasmuch as I have in the past, for as long as it interests me.

Similarly, a donation made in this way will probably not make me work on this
software much more, unless I get so many donations that I can consider working
on free software full time (let's all have a chuckle at that together).

To donate, log into PayPal and send money to autarch@urth.org, or use the
button at L<http://www.urth.org/~autarch/fs-donation.html>.

=head1 AUTHOR

Dave Rolsky <autarch@urth.org>

=head1 CONTRIBUTORS

=for stopwords Alexey Molchanov Alfie John Bron Gondwana Daisuke Maki David Pinkowitz Iain Truskett Joshua Hoblitt Karen Etheridge karupanerura Olaf Alders Peter Rabbitson

=over 4

=item *

Alexey Molchanov <alexey.molchanov@gmail.com>

=item *

Alfie John <alfiej@fastmail.fm>

=item *

Bron Gondwana <brong@fastmail.fm>

=item *

Daisuke Maki <dmaki@cpan.org>

=item *

David Pinkowitz <dave@pinkowitz.com>

=item *

Iain Truskett <deceased>

=item *

Joshua Hoblitt <jhoblitt@cpan.org>

=item *

Karen Etheridge <ether@cpan.org>

=item *

karupanerura <karupa@cpan.org>

=item *

Olaf Alders <olaf@wundersolutions.com>

=item *

Peter Rabbitson <ribasushi@cpan.org>

=back

=head1 COPYRIGHT AND LICENSE

This software is copyright (c) 2016 by Dave Rolsky.

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

=cut