perl/IsoTime.pm

   1 #
   2 # Utility routines for handling Iso 8601 date time groups
   3 #
   4 # $Id$
   5 #
   6 # Copyright (c) Dirk Koopman, G1TLH
   7 #
   8
   9 use strict;
  10
  11 package IsoTime;
  12
  13 use Date::Parse;
  14
  15 use vars qw($VERSION $BRANCH $year $month $day $hour $min $sec @days @ldays);
  16 $VERSION = sprintf( "%d.%03d", q$Revision$ =~ /(\d+)\.(\d+)/ );
  17 $BRANCH = sprintf( "%d.%03d", q$Revision$ =~ /\d+\.\d+\.(\d+)\.(\d+)/  || (0,0));
  18 $main::build += $VERSION;
  19 $main::branch += $BRANCH;
  20
  21 @days = (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
  22 @ldays = (31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
  23
  24 # is it a leap year?
  25 sub _isleap
  26 {
  27         my $year = shift;
  28         return ($year % 4 == 0 && ($year % 100 != 0 || $year % 400 == 0)) ? 1 : 0;
  29 }
  30
  31 sub full
  32 {
  33         return sprintf "%04d%02d%02dT%02d%02d%02d", $year, $month, $day, $hour, $min, $sec;
  34 }
  35
  36 sub dayminsec
  37 {
  38         return sprintf "%02dT%02d%02d%02d", $day, $hour, $min, $sec;
  39 }
  40
  41 sub daymin
  42 {
  43         return sprintf "%02dT%02d%02d", $day, $hour, $min;
  44 }
  45
  46 sub update
  47 {
  48         my $t = shift || time;
  49         ($sec,$min,$hour,$day,$month,$year) = gmtime($t);
  50         $month++;
  51         $year += 1900;
  52 }
  53
  54 sub unixtime
  55 {
  56         my $iso = shift;
  57
  58         # get the correct month and year if it is a short date
  59         if (my ($d) = $iso =~ /^(\d\d)T\d\d\d\d/) {
  60                 if ($d == $day) {
  61                         $iso = sprintf("%04d%02d", $year, $month) . $iso;
  62                 } else {
  63                         my $days = _isleap($year) ? $ldays[$month-1] : $days[$month-1];
  64                         my ($y, $m) = ($year, $month);
  65                         if ($d < $day) {
  66                                 if ($day - $d > $days / 2) {
  67                                         if ($month == 1) {
  68                                                 $y = $year - 1;
  69                                                 $m = 12;
  70                                         } else {
  71                                                 $m = $month - 1;
  72                                         }
  73                                 }
  74                         } else {
  75                                 if ($d - $day > $days / 2) {
  76                                         if ($month == 12) {
  77                                                 $y = $year + 1;
  78                                                 $m = 1;
  79                                         } else {
  80                                                 $m = $month + 1;
  81                                         }
  82                                 }
  83                         }
  84                         $iso = sprintf("%04d%02d", $y, $m) . $iso;
  85                 }
  86         }
  87         return str2time($iso);
  88 }
  89 1;