Message/Field/Date.pm


=head1 NAME

Message::Field::Date --- Perl module for various styles of 
date-time used in Internet messages and so on

=cut

package Message::Field::Date;
use strict;
use vars qw(%DEFAULT @ISA %MONTH %REG $VERSION %ZONE);
$VERSION=do{my @r=(q$Revision: 1.11 $=~/\d+/g);sprintf "%d."."%02d" x $#r,@r};
require Message::Field::Structured;
push @ISA, qw(Message::Field::Structured);
use Time::Local 'timegm_nocheck';
use overload '0+' => sub { $_[0]->{date_time} },
             fallback => 1;

%REG = %Message::Util::REG;
        $REG{M_dt_rfc822} = qr!(?:[A-Za-z]+     ## Day of week
                [\x09\x20,]*)?  ([0-9]+)        ## Day
                [\x09\x20/-]*   ([A-Za-z]+)     ## Month
                [\x09\x20/-]*   ([0-9]+)        ## Year
                [\x09\x20:Tt-]+ ([0-9]+)        ## Hour
                [\x09\x20:]+    ([0-9]+)        ## Minute
                [\x09\x20:]*    ([0-9]+)?       ## Second
                ([\x09\x20 0-9A-Za-z+-]+)!x;    ## Zone
        $REG{M_dt_iso8601} = qr!        ([0-9]{4,})     ## Year
                   [\x09\x20.:/-]+      ([0-9]+)        ## Month
                   [\x09\x20.:/-]+      ([0-9]+)        ## Day
                (?:[\x09\x20.:Tt-]+     ([0-9]+)        ## Hour
                   [\x09\x20.:]+        ([0-9]+)        ## Minute
                (?:[\x09\x20.:]+        ([0-9]+)        ## Second
                (?:[\x09\x20.:]+        ([0-9]+))?)?)?  ## frac.
                ([\x09\x20 0-9A-Za-z:.+-]*)     !x;     ## Zone.
        $REG{M_dt_rfc733} = qr!(?:[A-Za-z]+     ## Day of week
                [\x09\x20,]*)?  ([0-9]+)        ## Day
                [\x09\x20/-]*   ([A-Za-z]+)     ## Month
                [\x09\x20/-]*   ([0-9]+)        ## Year
                [\x09\x20:Tt-]+ ([0-9][0-9])    ## Hour
                [\x09\x20:]*    ([0-9][0-9])    ## Minute
                [\x09\x20:]*    ([0-9][0-9])?   ## Second
                ([\x09\x20 0-9A-Za-z+-]+)!x;    ## Zone
        $REG{M_dt_rfc724} = qr!(?:[A-Za-z]+     ## Day of week
                [\x09\x20,]*)?  ([0-9][0-9]?)   ## Month
                [\x09\x20/]+    ([0-9][0-9]?)   ## Day
                [\x09\x20/]+    ([0-9]{2,})     ## Year
                [\x09\x20:Tt-]+ ([0-9][0-9])    ## Hour
                [\x09\x20:]*    ([0-9][0-9])    ## Minute
                [\x09\x20:]*    ([0-9][0-9])?   ## Second
                ([\x09\x20 0-9A-Za-z+-]+)!x;    ## Zone
        
$REG{M_rfc724_slash_date} = qr#([0-9]+)$REG{FWS}/$REG{FWS}([0-9]+)$REG{FWS}/$REG{FWS}([0-9]+)$REG{WSP}+([0-9][0-9])$REG{FWS}(?::$REG{FWS})?([0-9][0-9])(?:$REG{FWS}(?::$REG{FWS})?([0-9][0-9]))?$REG{FWS}((?:-$REG{FWS})?[A-Za-z]+|[+-]$REG{WSP}*[0-9]+)#;
$REG{M_asctime} = qr/[A-Za-z]+$REG{FWS}([A-Za-z]+)$REG{FWS}([0-9]+)$REG{WSP}+([0-9]+)$REG{FWS}:$REG{FWS}([0-9]+)$REG{FWS}:$REG{FWS}([0-9]+)$REG{WSP}+([0-9]+)/;
$REG{M_iso8601_date_time} = qr/([0-9]+)-([0-9]+)-([0-9]+)[Tt]([0-9]+):([0-9]+):([0-9]+)(?:.([0-9]+))?(?:[Zz]|([+-])([0-9]+):([0-9]+))/;

=head1 CONSTRUCTORS

The following methods construct new objects:

=over 4

=cut

## Initialize of this class -- called by constructors
%DEFAULT = (
    -_MEMBERS   => [qw|date_time secfrac|],
    -_METHODS   => [qw|unix_time second_fraction
                       comment_add comment_count comment_item comment_delete|],
    -date_format        => 'string',    ## 'unix' / 1*ALPHA
    #field_param_name
    #field_name
    #format
    #hook_encode_string
    #hook_decode_string
    -output_comment     => 1,
    -fmt2str    => {
        CC      => sub { sprintf $_[2]->{_fmt},         ## Support AD only
                         (($_[1]->{$_[2]->{_prefix}.'tm'}->[5] + 1899) / 100) + 1 },
        YYYY    => sub { $_[2]->{_fmt} =~ tr/2/4/;
                         sprintf $_[2]->{_fmt}, 
                                 $_[1]->{$_[2]->{_prefix}.'tm'}->[5] + 1900 },
        YY      => sub { sprintf $_[2]->{_fmt}, 
                         substr ($_[1]->{$_[2]->{_prefix}.'tm'}->[5], -2) },
        MM      => sub { sprintf $_[2]->{_fmt},
                                 $_[1]->{$_[2]->{_prefix}.'tm'}->[4] + 1 },
        Mon     => sub { qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec)
                           [$_[1]->{$_[2]->{_prefix}.'tm'}->[4]] },
        Month   => sub { qw(January February March April May June
                            July August September October November December)
                           [$_[1]->{$_[2]->{_prefix}.'tm'}->[4]] },
        DD      => sub { sprintf $_[2]->{_fmt}, $_[1]->{$_[2]->{_prefix}.'tm'}->[3] },
        Wdy     => sub { qw(Sun Mon Tue Wed Thu Fri Sat)
                           [$_[1]->{$_[2]->{_prefix}.'tm'}->[6]] },
        Weekday => sub { qw(Sunday Monday Tuesday Wednesday Thursday Friday Saturday)
                           [$_[1]->{$_[2]->{_prefix}.'tm'}->[6]] },
        shun    => sub {
          my @alphabet = split /:/, $_[2]->{alphabet} || 'abcc';
          my $day = $_[1]->{$_[2]->{_prefix}.'tm'}->[3];
          $day <= 10? $alphabet[0]:     ##  1 - 10 joujun
          $day <= 20? $alphabet[1]:     ## 11 - 20 chuujun
                      $alphabet[2];     ## 21 - 31 gejun
        },
        HH      => sub { sprintf $_[2]->{_fmt}, $_[1]->{$_[2]->{_prefix}.'tm'}->[2] },
        TT      => sub { sprintf $_[2]->{_fmt}, $_[1]->{$_[2]->{_prefix}.'tm'}->[1] },
        SS      => sub { sprintf $_[2]->{_fmt}, $_[1]->{$_[2]->{_prefix}.'tm'}->[0] },
        unix    => sub { $_[1]->{$_[2]->{_prefix}.'unix'} },
        frac    => sub { $_[0]->{secfrac} },
        zsign   => sub { $_[1]->{zone}->[0] > 0 ? '+' : '-' },
        zHH     => sub { sprintf $_[2]->{_fmt}, $_[1]->{zone}->[1] },
        zTT     => sub { sprintf $_[2]->{_fmt}, $_[1]->{zone}->[2] },
    },
    -use_comment        => 1,
    -use_military_zone  => +1,  ## +1 / -1 / 0
    -zone       => [+1, 0, 0],
    -zone_default_string        => '-0000',
);

%MONTH = (
  JAN   => 1,   JANUARY => 1,
  FEB   => 2,   FEBRUARY        => 2,
  MAR   => 3,   MARCH   => 3,
  APR   => 4,   APRIL   => 4,
  MAY   => 5,
  JUN   => 6,   JUNE    => 6,
  JUL   => 7,   JULY    => 7,
  AUG   => 8,   AUGUST  => 8,
  SEP   => 9,   SEPTEMBER       => 9,   SEPT    => 9,
  OCT   => 10,  OCTOBER => 10,
  NOV   => 11,  NOVEMBER        => 11,
  DEC   => 12,  DECEMBER        => 12,
);

%ZONE = (       ## NA = Northern America
  ADT   => [-1,  3,  0],        ## (NA)Atlantic Daylight        733
  CHST  => [-1, 10,  0],        ## Alaska-Hawaii Standard
  AST   => [-1,  4,  0],        ## (NA)Atlantic Standard        733
  AT    => [-1,  2,  0],        ## Azores
  BDT   => [-1, 10,  0],        ##      733
  BST   => [-1, 11,  0],        ##      733
  #BST  => [+1,  1,  0],        ## British Summer
  #BST  => [-1,  3,  0],        ## Brazil Standard
  BT    => [+1,  3,  0],        ## Baghdad
  CADT  => [+1, 10, 30],        ## Central Australian Daylight
  CAST  => [+1,  9, 30],        ## Central Australian Standard
  CAT   => [-1, 10,  0],        ## Central Alaska
  CCT   => [+1,  8,  0],        ## China Coast
  CDT   => [-1,  5,  0],        ## (NA)Central Daylight 733, 822
  CET   => [+1,  1,  0],        ## Central European
  CEST  => [+1,  2,  0],        ## Central European Daylight
  CST   => [-1,  6,  0],        ## (NA)Central Standard 733, 822
  EADT  => [+1, 11,  0],        ## Eastern Australian Daylight
  EADT  => [+1, 10,  0],        ## Eastern Australian Standard
  ECT   => [+1,  1,  0],        ## Central European (French)
  EDT   => [-1,  4,  0],        ## (NA)Eastern Daylight 733, 822
  EEST  => [+1,  3,  0],        ## Eastern European Summer
  EET   => [+1,  2,  0],        ## Eastern Europe       1947
  EST   => [-1,  5,  0],        ## (NA)Eastern Standard 733, 822
  EWT   => [-1,  4,  0],        ## U.S. Eastern War Time
  FST   => [+1,  2,  0],        ## French Summer
  FWT   => [+1,  1,  0],        ## French Winter
  GDT   => [+1,  1,  0],        ##      724
  GMT   => [+1,  0,  0],        ## Greenwich Mean       733, 822
  #GST  => [-1,  3,  0],        ## Greenland Standard
  GST   => [+1, 10,  0],        ## Guam Standard
  HDT   => [-1,  9,  0],        ## Hawaii Daylight      733
  HKT   => [+1,  8,  0],        ## Hong Kong
  HST   => [-1, 10,  0],        ## Hawaii Standard      733
  IDLE  => [+1, 12,  0],        ## International Date Line East
  IDLW  => [-1, 12,  0],        ## International Date Line West
  IDT   => [+1,  3,  0],
  IST   => [+1,  2,  0],        ## Israel standard
  #IST  => [+1,  5, 30],        ## Indian standard
  IT    => [+1,  3, 30],        ## Iran
  JST   => [+1,  9,  0],        ## Japan Central Standard
  JT    => [+1,  7, 30],        ## Java
  KDT   => [+1, 10,  0],        ## Korean Daylight
  KST   => [+1,  9,  0],        ## Korean Standard
  LOCAL => [-1,  0,  0],
  MDT   => [-1,  6,  0],        ## (NA)Mountain Daylight        733, 822
  MET   => [+1,  0,  0],        ## Middle European
  METDST        => [+1,  2,  0],
  MEST  => [+1,  2,  0],        ## Middle European Summer
  MEWT  => [+1,  0,  0],        ## Middle European Winter
  MEZ   => [+1,  0,  0],        ## Central European (German)
  MST   => [-1,  7,  0],        ## (NA)Mountain Standard        733, 822
  NDT   => [-1,  2, 30],        ## Newfoundland Daylight
  NFT   => [-1,  3, 30],        ## Newfoundland Standard
  NST   => [-1,  3, 30],        ## Newfoundland Standard        733
  #NST  => [-1,  6, 30],        ## North Sumatra
  NT    => [-1, 11,  0],        ## Nome
  NZD   => [+1, 13,  0],        ## New Zealand Daylight
  NZT   => [+1, 12,  0],        ## New Zealand
  NZDT  => [+1, 13,  0],        ## New Zealand Daylight
  NZST  => [+1, 12,  0],        ## New Zealand Standard
  PDT   => [-1,  7,  0],        ## (NA)Pacific Daylight 733, 822
  PST   => [-1,  8,  0],        ## (NA)Pacific Standard 733, 822
  SET   => [+1,  1,  0],        ## Seychelles
  SST   => [+1,  2,  0],        ## Swedish Summer
  #SST  => [+1,  7,  0],        ## South Sumatra
  SWT   => [+1,  1,  0],        ## Swedish Winter
  UKR   => [+1,  2,  0],        ## Ukraine
  UT    => [+1,  0,  0],        ##      822
  UTC   => [+1,  0,  0],
  WADT  => [+1,  8,  0],        ## West Australian Daylight
  WAT   => [-1,  0,  0],        ## West Africa
  WET   => [+1,  0,  0],        ## Western European
  WST   => [+1,  8,  0],        ## West Australian Standard
  YDT   => [-1,  8,  0],        ## Yukon Daylight       733
  YST   => [-1,  9,  0],        ## Yukon Standard       733
  Z     => [+1,  0,  0],        ##      822, ISO 8601
  ZP4   => [+1,  4,  0],        ## Z+4
  ZP5   => [+1,  5,  0],        ## Z+5
  ZP6   => [+1,  6,  0],        ## Z+6
);

## -use_military_zone => +1 / -1 / 0
##   Whether military zone names are understood or not.
##   +1  Admits them and treats as standard value.  (eg. "A" = +0100)
##   -1  Admits them but treats as negative value.  (eg. "A" = -0100)
##    0  They are ignored and zone is set as -0000. (eg. "A" = -0000)
##   Because of typo in BNF comment of RFCs 733 and 822,
##   quite a few implemention use these values incorrectly.
##   As a result, these zone names carry no worthful information.
##   RFC 2822 recommends these names be taken as '-0000' (i.e.
##   unknown zone).

sub _set_military_zone_name ($) {
  my $self = shift;
  my $mode = $self->{option}->{use_military_zone};
  my $i = 0;
  if ($mode == 0) {
    for my $letter ('A'..'Y') {$ZONE{$letter} = [-1, 0, 0]} return;
  }
  for my $letter ('Z', 'A'..'I', 'K'..'M') {
    $ZONE{$letter} = [+1*$mode, $i++, 0];
  }  $i = 1;
  for my $letter ('N'..'Y') {
    $ZONE{$letter} = [-1*$mode, $i++, 0];
  }
}

sub _init ($;%) {
  my $self = shift;
  my $DEFAULT = Message::Util::make_clone (\%DEFAULT);
  my %option = @_;
  $self->SUPER::_init (%$DEFAULT, %option);
  $self->{date_time} = $option{unix} if defined $option{unix};
  $self->{secfrac} = $option{frac} if defined $option{frac};
  
  my $format = $self->{option}->{format};
  if ($format =~ /rfc2822/) {
    $self->{option}->{use_military_zone} = 0;
  }
  
  $self->_set_military_zone_name;
}

=item $date = Message::Field::Date->new ([%options])

Constructs a new object.  You might pass some options as parameters 
to the constructor.

=cut

## Inherited

=item $date = Message::Field::Date->parse ($field-body, [%options])

Constructs a new object with given field body.  You might pass 
some options as parameters to the constructor.

=cut

sub parse ($$;%) {
  my $class = shift;
  my $self = bless {}, $class;
  my $body = shift;
  $self->_init (@_);
  ($body, @{$self->{comment}})
    = $self->Message::Util::delete_comment_to_array ($body)
    if $self->{option}->{use_comment};
  $body =~ s/^$REG{WSP}+//;  $body =~ s/$REG{WSP}+$//;
  if ($self->{option}->{date_format} eq 'unix') {
    $self->{date_time} = int ($body);
  } elsif ($body =~ /^$REG{M_dt_rfc822}$/x) {
    my ($day, $month, $year, $hour, $minute, $second, $zone)
     = ($1, uc $2, $3, $4, $5, $6, uc $7);
    $month = $MONTH{$month} || 1;
    $year = $self->_obvious_year ($year) if length($year)<4;
    my ($zone_sign, $zone_hour, $zone_minute) = $self->_zone_string_to_array ($zone);
    eval '$self->{date_time} = timegm_nocheck 
      ($second, $minute-($zone_sign*$zone_minute), $hour-($zone_sign*$zone_hour), 
       $day, $month-1, $year);';
    $self->{secfrac} = '';
    $self->{option}->{zone} = [$zone_sign, $zone_hour, $zone_minute];
  } elsif ($body =~ /^$REG{M_dt_iso8601}$/x) {
    my ($year,$month,$day,$hour,$minute,$second,$secfrac,$zone)
     = ($1, $2, $3, $4, $5, $6, $7, $8);
    my ($zone_sign, $zone_hour, $zone_minute) = $self->_zone_string_to_array ($zone);
    eval '$self->{date_time} = timegm_nocheck 
      ($second, $minute-($zone_sign*$zone_minute), $hour-($zone_sign*$zone_hour), 
       $day, $month-1, $year);';
    $self->{secfrac} = $secfrac;
    $self->{option}->{zone} = [$zone_sign, $zone_hour, $zone_minute];
  } elsif ($body =~ /^$REG{M_dt_rfc733}$/x) {
    my ($day, $month, $year, $hour, $minute, $second, $zone)
     = ($1, uc $2, $3, $4, $5, $6, uc $7);
    $month = $MONTH{$month} || 1;
    $year = $self->_obvious_year ($year) if length($year)<4;
    my ($zone_sign, $zone_hour, $zone_minute) = $self->_zone_string_to_array ($zone);
    eval '$self->{date_time} = timegm_nocheck 
      ($second, $minute-($zone_sign*$zone_minute), $hour-($zone_sign*$zone_hour), 
       $day, $month-1, $year);';
    $self->{secfrac} = '';
    $self->{option}->{zone} = [$zone_sign, $zone_hour, $zone_minute];
  } elsif ($body =~ /^$REG{M_dt_rfc724}$/x) {
    my ($month, $day, $year, $hour, $minute, $second, $zone)
     = ($1, $2, $3, $4, $5, $6, uc $7);
    $year = $self->_obvious_year ($year) if length($year)<4;
    my ($zone_sign, $zone_hour, $zone_minute) = $self->_zone_string_to_array ($zone);
    eval '$self->{date_time} = timegm_nocheck 
      ($second, $minute-($zone_sign*$zone_minute), $hour-($zone_sign*$zone_hour), 
       $day, $month-1, $year);';
    $self->{secfrac} = '';
    $self->{option}->{zone} = [$zone_sign, $zone_hour, $zone_minute];
  #} elsif ($body =~ /^[0-9]+$/) {
  #  $self->{date_time} = $&;
  } else {
    ## From HTTP::Date (revision 1.40) by Gisle Aas
    #$body =~ s/^\s+//;  # kill leading space
    $body =~ s/^(?:Sun|Mon|Tue|Wed|Thu|Fri|Sat)[a-z]*,?\s*//i; # Useless weekday
    my ($day, $month, $year, $hour, $minute, $second);
    my ($secfrac, $zone, $ampm) = ('', $self->{option}->{zone_default_string});
    
    # Then we are able to check for most of the formats with this regexp
    (($day,$month,$year,$hour,$minute,$second,$zone) =
      $body =~ m"^
        (\d\d?)               # day
          (?:\s+|[-\/])
        (\w+)                 # month
          (?:\s+|[-\/])
        (\d+)                 # year
        (?:
            (?:\s+|:)       # separator before clock
          (\d\d?):(\d\d)     # hour:min
          (?::(\d\d))?       # optional seconds
        )?                    # optional clock
          \s*
        ([-+]?\d{2,4}|(?![APap][Mm]\b)[A-Za-z]+)? # timezone
      $"x)
    
    ||
    
    # Try the ctime and asctime format
    (($month, $day, $hour, $minute, $second, $zone, $year) =
    $body =~ m"^
      (\w{1,3})             # month
        \s+
      (\d\d?)               # day
        \s+
      (\d\d?):(\d\d)        # hour:min
      (?::(\d\d))?          # optional seconds
        \s+
      (?:([A-Za-z]+)\s+)?   # optional timezone
      (\d+)                 # year
    $"x)
    
    ||
    
    # Then the Unix 'ls -l' date format
    (($month, $day, $year, $hour, $minute, $second) =
    $body =~ m"^
      (\w{3})               # month
        \s+
      (\d\d?)               # day
        \s+
      (?:
        (\d\d\d\d) |       # year
        (\d{1,2}):(\d{2})  # hour:min
        (?::(\d\d))?       # optional seconds
      )
    $"x)
    
    ||
    
    # ISO 8601 format '1996-02-29 12:00:00 -0100' and variants
    (($year, $month, $day, $hour, $minute, $second, $secfrac, $zone) =
    $body =~ m"^
      (\d{4})              # year
        [-\/]?
      (\d\d?)              # numerical month
        [-\/]?
      (\d\d?)              # day
      (?:
          (?:\s+|[-:Tt])  # separator before clock
        (\d\d?):?(\d\d)    # hour:min
        (?:
          :?
          (\d\d)
          (?:\.?(\d+))? ## optional second frac.
        )?      # optional seconds
      )?                    # optional clock
        \s*
      ([-+]?\d\d?:?(:?\d\d)?
      |Z|z)?               # timezone  (Z is 'zero meridian', i.e. GMT)
      
    $"x)
    
    ||
    
    # ISO 8601 like format '96-02-29 2:0:0 -0100' and variants
    (($year, $month, $day, $hour, $minute, $second, $secfrac, $zone) =
    $body =~ m"^
      (\d+)              # year
        [-/]
      (\d\d?)              # numerical month
        [-/]
      (\d\d?)              # day
      (?:
          (?:\s+|[-:Tt])  # separator before clock
        (\d\d?):(\d+)    # hour:min
        (?:
          :
          (\d+)
          (?:\.(\d+))   ## optional second frac.
        )?      # optional seconds
      )?                    # optional clock
        \s*
      ([-+]?\d+(:\d+)?
      |Z|z)?               # timezone  (Z is 'zero meridian', i.e. GMT)
      
    $"x)
    
    ||
    
    # Windows 'dir' 11-12-96  03:52PM
    (($month, $day, $year, $hour, $minute, $ampm) =
      $body =~ m"^
        (\d{2})                # numerical month
          -
        (\d{2})                # day
          -
        (\d{2})                # year
          \s+
        (\d\d?):(\d\d)([APap][Mm])  # hour:min AM or PM
      $"x)
    
    #||
    #return;  # unrecognized format
    ;
    
    $day ||= 1;
    # Translate month name to number
    $month ||= 1;
    $month = $MONTH{uc $month}
             || int ($month);
    
    # If the year is missing, we assume first date before the current,
    # because of the formats we support such dates are mostly present
    # on "ls -l" listings.
    unless (defined $year) {
      my $cur_mon;
      ($cur_mon, $year) = (localtime)[4, 5];
      $year += 1900;  $cur_mon++;
      $year-- if $month > $cur_mon;
    } elsif (length($year) < 3) {
      $year = $self->_obvious_year ($year);
    }
    
    # Make sure clock elements are defined
    $hour       = 0 unless defined($hour);
    $minute     = 0 unless defined($minute);
    $second     = 0 unless defined($second);
    
    # Compensate for AM/PM
    if ($ampm) {
      $ampm = uc $ampm;
      $hour = 0 if $hour == 12 && $ampm eq 'AM';
      $hour += 12 if $ampm eq 'PM' && $hour != 12;
    }
    
    my ($zone_sign, $zone_hour, $zone_minute) = $self->_zone_string_to_array ($zone);
    eval '$self->{date_time} = timegm_nocheck 
      ($second, $minute-($zone_sign*$zone_minute), $hour-($zone_sign*$zone_hour), 
       $day, $month-1, $year);';
    $self->{secfrac} = $secfrac;
    $self->{option}->{zone} = [$zone_sign, $zone_hour, $zone_minute];
  }
  $self;
}

sub zone ($;$) {
  my $self = shift;
  my $newzone = shift;
  if (ref $newzone) {
    $self->{option}->{zone} = $newzone;
  } elsif (length $newzone) {
    $self->{option}->{zone} = [$self->_zone_string_to_array ($newzone)];
  }
  $self->{option}->{zone};
}

## Find "obvious" year
sub _obvious_year ($$) {
  my $self = shift;
  my $year = shift;
  if ($self->{option}->{format} =~ /mail|news/) {
    ## RFC 2822
    if    ( 0 <=$year && $year <   50) {$year += 2000}
    elsif (50 < $year && $year < 1000) {$year += 1900}
  } else {
    ## RFC 2616
      my $cur_yr = (localtime)[5] + 1900;
      my $m = $cur_yr % 100;
      my $tmp = $year;
      $year += $cur_yr - $m;
      $m -= $tmp;
      $year += ($m > 0) ? 100 : -100 if abs($m) > 50;
  }
  $year;
}

=back

=head1 METHODS

=over 4


=head2 $self->unix_time ([$new_time])

Returns or set the unix-time (seconds from the Epoch).

=cut

sub unix_time ($;$) {
  my $self = shift;
  my $new_time = shift;
  if (defined $new_time) {
    $self->{date_time} = $new_time + 0;
  }
  $self->{date_time};
}

sub set_datetime ($@) {
  my $self = shift;
  my ($year,$month,$day,$hour,$minute,$second,%misc) = @_;
  my ($zone_sign, $zone_hour, $zone_minute)
    = $self->_zone_string_to_array ($misc{zone});
  eval '$self->{date_time} = timegm_nocheck 
    ($second, $minute-($zone_sign*$zone_minute), $hour-($zone_sign*$zone_hour), 
     $day, $month-1, $year);';
  $self->{secfrac} = $misc{secfrac};
  $self->{option}->{zone} = [$zone_sign, $zone_hour, $zone_minute];
}

=head2 $self->second_fraction ([$new_fraction])

Returns or set the decimal fraction of a second.
Value is a string containing of only [0-9]
or empty string.

=cut

sub second_fraction ($;$) {
  my $self = shift;
  my $new_fraction = shift;
  if (defined $new_fraction) {
    $self->{secfrac} = $new_fraction unless $new_fraction =~ /[^0-9]/;
  }
  $self->{secfrac};
}

=item $field-body = $date->stringify ()

Returns C<field-body> as a string.

=cut

sub stringify ($;%) {
  my $self = shift;
  my %o = @_;
  my %option = %{$self->{option}};
  for (grep {/^-/} keys %o) {$option{substr ($_, 1)} = $o{$_}}
  unless ($option{format_template}) {
    if ($option{format} =~ /rfc2822|rfc1123|son-of-rfc1036|usefor|mime/) {
      $option{format_template} = '%Wdy(local);, %DD(local); %Mon(local); %YYYY(local); %HH(local);:%TT(local);:%SS(local); %zsign;%zHH;%zTT;';
    } elsif ($option{format} =~ /http/) {
      $option{format_template} = '%Wdy;, %DD; %Mon; %YYYY; %HH;:%TT;:%SS; GMT';
    } elsif ($option{format} =~ /rfc822|rfc1036/) {
      $option{format_template} = '%Wdy(local);, %DD(local); %Mon(local); %YY(local); (%YYYY(local);) %HH(local);:%TT(local);:%SS(local); %zsign;%zHH;%zTT;';
    } elsif ($option{format} =~ /rfc850/) {
      $option{format_template} = '%Weekday;, %DD;-%Mon;-%YY; %HH;:%TT;:%SS; GMT';
    } elsif ($option{format} =~ /asctime/) {
      $option{format_template} = '%Wdy; %Mon; %DD(pad=>SP); %HH;:%MM;:%SS; %YYYY;';
    #} elsif ($option{format} =~ /date\(1\)/) {
    #  $option{format_template} = '%Wdy; %Mon; %DD(pad=>SP); %HH;:%MM;:%SS; GMT %YYYY;';
    } elsif ($option{format} =~ /un[i*]x/) {    ## :-)
      $option{format_template} = '%unix;';
    } else {    ## ISO 8601 (IETF)
      $option{format_template} = '%YYYY(local);-%MM(local);-%DD(local);T%HH(local);:%TT(local);:%SS(local);%frac(prefix=>.);%zsign;%zHH;:%zTT;';
    }
  }
  $self->_date2str (\%option)
    . (($option{output_comment} && @{$self->{comment}} > 0)?
        ' ' . $self->_comment_stringify: '');
}
*as_string = \&stringify;
*as_plain_string = \&stringify;
## You should use stringify instead of as_rfc2822_time
sub as_rfc2822_time ($@) {
  shift->stringify (-format => 'mail-rfc2822', @_);
}

sub _date2str ($\%\%) {
  my $self = shift;
  my $option = shift;
  my $gparam = shift;
  my $template  = $option->{format_template};
  my $time      = $self->{date_time};
  $time = $option->{date_time} if defined $option->{date_time};
  my $zone      = $option->{zone};
  if (ref $zone) { }
  elsif (length $zone) {$zone = [$self->_zone_string_to_array ($zone)]}
  my $l_time  = $time + $zone->[0] * ($zone->[1] * 60 + $zone->[2]) * 60;
  my %time = (unix      => $time,
              tm        => [gmtime ($time)],
              l_unix    => $l_time,
              l_tm      => [gmtime ($l_time)],
              zone      => $zone);
  $template =~ s{%([A-Za-z0-9_]+)(?:\(([A-Za-z0-9,.:\x09\x20=>_-]*)\))?;}{
    my ($f, $a) = ($1, $2);
    my $function = $option->{fmt2str}->{$f};
    if (ref $function) {
      my %a;
      for (split /[\x09\x20]*,[\x09\x20]*/, $a) {
        if (/^([^=]+)=>(.+)$/) {$a{$1} = $2}
        else {$a{$_} = 1}
      }
      $a{_prefix} = $a{local}? 'l_': '';
      $a{_fmt} = $a{pad} eq 'SP'?   '%2d':
                 $a{pad} eq 'none'? '%d':
                                    '%02d';
      my $r = &$function ($self, \%time, \%a, $gparam);
      length $r? $a{prefix}.$r.$a{suffix}: '';
    } elsif (length $function) {
      $function;
    } else {
      "[$f: undef]";
    }
  }gex;
  $template;
}


sub _zone_string_to_array ($$;$) {
  my $self = shift;
  my $zone = shift;
  return (+1, 0, 0) unless defined $zone;
  my $format = shift;
  my @azone = [+1, 0, 0];
  $zone =~ tr/\x09\x20//d;
    if ($zone =~ /([+-])([0-9][0-9])([0-9][0-9])/) {
      @azone = ("${1}1", $2, $3);
    } elsif ($zone =~ /([+-]?)([0-9]+)(?:[:.-]([0-9]+))?/) {
      @azone = ("${1}1", $2, $3);
    } else { $zone =~ tr/-//d;
      if (ref $ZONE{$zone}) {@azone = @{$ZONE{$zone}}}
      elsif ($zone) {@azone = (-1, 0, 0)}
    }
  # }
  @azone;
}

=item $option-value = $date->option ($option-name)

Gets option value.

=item $date->option ($option-name, $option-value, ...)

Set option value(s).  You can pass multiple option name-value pair
as parameter when setting.

=item $clone = $date->clone ()

Returns a copy of the object.

=cut

## option, clone, method_available: Inherited

=head1 EXAMPLE

  use Message::Field::Date;
  
  print Message::Field::Date->new (unix => time, 
    -zone => '+0900'),"\n";     ## Thu, 16 May 2002 17:53:44 +0900
  print Message::Field::Date->new (unix => time, 
    -format_template =>         ## Century: 21, Year: 02, Month: 05
      'Century: %CC;, Year: %YY;, Month: %MM;'),"\n";
  
  my $field_body = '04 Feb 2002 00:12:33 CST';
  my $field = Message::Field::Date->parse ($field_body);
  
  print "RFC 2822:\t", $field->stringify (-format => 'mail-rfc2822'), "\n";
  print "HTTP preferred:\t", $field->stringify (-format => 'http-1.1'), "\n";
  print "ISO 8601:\t", $field->stringify (-format => 'mail-cpim'), "\n";
  ## RFC 2822:       Mon, 04 Feb 2002 00:12:33 -0600
  ## HTTP preferred: Mon, 04 Feb 2002 06:12:33 GMT
  ## ISO 8601:       2002-02-04T00:12:33-06:00

=head1 LICENSE

Copyright 2002 wakaba E<lt>w@suika.fam.cxE<gt>.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.

=head1 CHANGE

See F<ChangeLog>.
$Date: 2002/06/16 10:42:06 $

=cut

1;