selfforum-cgi/shared/Time/German.pm

   1 package Time::German;
   2
   3 ################################################################################
   4 #                                                                              #
   5 # File:        shared/Time/German.pm                                           #
   6 #                                                                              #
   7 # Authors:     Andre Malo       <nd@o3media.de>, 2001-06-10                    #
   8 #                                                                              #
   9 # Description: determine time offset German Time <=> GMT (seconds)             #
  10 #                                                                              #
  11 ################################################################################
  12
  13 use strict;
  14 use vars qw(
  15   @EXPORT
  16   $VERSION
  17 );
  18
  19 ################################################################################
  20 #
  21 # Version check
  22 #
  23 $VERSION = do { my @r =(q$Revision$ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
  24
  25 ################################################################################
  26 #
  27 # Export
  28 #
  29 use base 'Exporter';
  30 @EXPORT = qw(localtime);
  31
  32 ################################################################################
  33 #
  34 # german summertime 1980-1995 (ydays)
  35 #
  36 my %summertime = (
  37   80 => [96, 271],
  38   81 => [87, 269],
  39   82 => [86, 268],
  40   83 => [85, 267],
  41   84 => [84, 273],
  42   85 => [89, 271],
  43   86 => [88, 270],
  44   87 => [87, 269],
  45   88 => [86, 268],
  46   89 => [84, 266],
  47   90 => [83, 272],
  48   91 => [89, 271],
  49   92 => [88, 270],
  50   93 => [86, 268],
  51   94 => [85, 267],
  52   95 => [84, 266]
  53 );
  54
  55 ### localtime () ###############################################################
  56 #
  57 # like 'localtime', but system independent
  58 #
  59 # Params: $time - time since epoch (GMT)
  60 #
  61 # Return: same as localtime, but german time ;-)
  62 #
  63 sub localtime (;$) {
  64   my $time = shift;
  65   $time = time unless defined $time;
  66
  67   my ($hour,$mday,$mon,$year,$wday,$yday) = (gmtime($time))[qw(2 3 4 5 6 7)];
  68   my $offset = 1;
  69
  70   # 1980 - 1995
  71   #
  72   if ($summertime{$year}) {
  73     $offset++ if (
  74       (
  75         $yday >  $summertime{$year} -> [0]  and
  76         $yday <  $summertime{$year} -> [1]
  77       ) or
  78       (
  79         $yday == $summertime{$year} -> [0]  and
  80         $hour >= 1
  81       ) or
  82       (
  83         $yday == $summertime{$year} -> [1]  and
  84         $hour <= 1
  85       )
  86     );
  87   }
  88
  89   # > 1995
  90   #
  91   elsif ($year > 95) {
  92     # determine last Sunday in March or October
  93     #
  94     my $limit = $mday + int((31-$mday)/7) * 7 - $wday if ($mon == 2 or $mon == 9);
  95
  96     $offset++ if (
  97       (
  98         $mon > 2          and
  99         $mon < 9
 100       ) or
 101       (
 102         $mon  == 2        and
 103         (
 104           $mday >  $limit  or
 105           $mday == $limit and
 106           $hour >= 1
 107         )
 108       ) or
 109       (
 110         $mon == 9         and
 111         (
 112           $mday <  $limit  or
 113           $mday == $limit and
 114           $hour <= 1
 115         )
 116       )
 117     );
 118   }
 119
 120   return gmtime($time + $offset * 3600);
 121 }
 122
 123 # keep 'require' happy
 124 1;
 125
 126 #
 127 #
 128 ### end of Time::German ########################################################