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