gitweb/static/js/lib/datetime.js

   1 // Copyright (C) 2007, Fredrik Kuivinen <frekui@gmail.com>
   2 //               2007, Petr Baudis <pasky@suse.cz>
   3 //          2008-2011, Jakub Narebski <jnareb@gmail.com>
   4
   5 /**
   6  * @fileOverview Datetime manipulation: parsing and formatting
   7  * @license GPLv2 or later
   8  */
   9
  10
  11 /* ............................................................ */
  12 /* parsing and retrieving datetime related information */
  13
  14 /**
  15  * used to extract hours and minutes from timezone info, e.g '-0900'
  16  * @constant
  17  */
  18 var tzRe = /^([+\-])([0-9][0-9])([0-9][0-9])$/;
  19
  20 /**
  21  * convert numeric timezone +/-ZZZZ to offset from UTC in seconds
  22  *
  23  * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
  24  * @returns {Number} offset from UTC in seconds for timezone
  25  *
  26  * @globals tzRe
  27  */
  28 function timezoneOffset(timezoneInfo) {
  29         var match = tzRe.exec(timezoneInfo);
  30         var tz_sign = (match[1] === '-' ? -1 : +1);
  31         var tz_hour = parseInt(match[2],10);
  32         var tz_min  = parseInt(match[3],10);
  33
  34         return tz_sign*(((tz_hour*60) + tz_min)*60);
  35 }
  36
  37 /**
  38  * return local (browser) timezone as offset from UTC in seconds
  39  *
  40  * @returns {Number} offset from UTC in seconds for local timezone
  41  */
  42 function localTimezoneOffset() {
  43         // getTimezoneOffset returns the time-zone offset from UTC,
  44         // in _minutes_, for the current locale
  45         return ((new Date()).getTimezoneOffset() * -60);
  46 }
  47
  48 /**
  49  * return local (browser) timezone as numeric timezone '(+|-)HHMM'
  50  *
  51  * @returns {String} locat timezone as -/+ZZZZ
  52  */
  53 function localTimezoneInfo() {
  54         var tzOffsetMinutes = (new Date()).getTimezoneOffset() * -1;
  55
  56         return formatTimezoneInfo(0, tzOffsetMinutes);
  57 }
  58
  59
  60 /**
  61  * Parse RFC-2822 date into a Unix timestamp (into epoch)
  62  *
  63  * @param {String} date: date in RFC-2822 format, e.g. 'Thu, 21 Dec 2000 16:01:07 +0200'
  64  * @returns {Number} epoch i.e. seconds since '00:00:00 1970-01-01 UTC'
  65  */
  66 function parseRFC2822Date(date) {
  67         // Date.parse accepts the IETF standard (RFC 1123 Section 5.2.14 and elsewhere)
  68         // date syntax, which is defined in RFC 2822 (obsoletes RFC 822)
  69         // and returns number of _milli_seconds since January 1, 1970, 00:00:00 UTC
  70         return Date.parse(date) / 1000;
  71 }
  72
  73
  74 /* ............................................................ */
  75 /* formatting date */
  76
  77 /**
  78  * format timezone offset as numerical timezone '(+|-)HHMM' or '(+|-)HH:MM'
  79  *
  80  * @param {Number} hours:    offset in hours, e.g. 2 for '+0200'
  81  * @param {Number} [minutes] offset in minutes, e.g. 30 for '-4030';
  82  *                           it is split into hours if not 0 <= minutes < 60,
  83  *                           for example 1200 would give '+0100';
  84  *                           defaults to 0
  85  * @param {String} [sep] separator between hours and minutes part,
  86  *                       default is '', might be ':' for W3CDTF (rfc-3339)
  87  * @returns {String} timezone in '(+|-)HHMM' or '(+|-)HH:MM' format
  88  */
  89 function formatTimezoneInfo(hours, minutes, sep) {
  90         minutes = minutes || 0; // to be able to use formatTimezoneInfo(hh)
  91         sep = sep || ''; // default format is +/-ZZZZ
  92
  93         if (minutes < 0 || minutes > 59) {
  94                 hours = minutes > 0 ? Math.floor(minutes / 60) : Math.ceil(minutes / 60);
  95                 minutes = Math.abs(minutes - 60*hours); // sign of minutes is sign of hours
  96                 // NOTE: this works correctly because there is no UTC-00:30 timezone
  97         }
  98
  99         var tzSign = hours >= 0 ? '+' : '-';
 100         if (hours < 0) {
 101                 hours = -hours; // sign is stored in tzSign
 102         }
 103
 104         return tzSign + padLeft(hours, 2, '0') + sep + padLeft(minutes, 2, '0');
 105 }
 106
 107 /**
 108  * translate 'utc' and 'local' to numerical timezone
 109  * @param {String} timezoneInfo: might be 'utc' or 'local' (browser)
 110  */
 111 function normalizeTimezoneInfo(timezoneInfo) {
 112         switch (timezoneInfo) {
 113         case 'utc':
 114                 return '+0000';
 115         case 'local': // 'local' is browser timezone
 116                 return localTimezoneInfo();
 117         }
 118         return timezoneInfo;
 119 }
 120
 121
 122 /**
 123  * return date in local time formatted in iso-8601 like format
 124  * 'yyyy-mm-dd HH:MM:SS +/-ZZZZ' e.g. '2005-08-07 21:49:46 +0200'
 125  *
 126  * @param {Number} epoch: seconds since '00:00:00 1970-01-01 UTC'
 127  * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
 128  * @returns {String} date in local time in iso-8601 like format
 129  */
 130 function formatDateISOLocal(epoch, timezoneInfo) {
 131         // date corrected by timezone
 132         var localDate = new Date(1000 * (epoch +
 133                 timezoneOffset(timezoneInfo)));
 134         var localDateStr = // e.g. '2005-08-07'
 135                 localDate.getUTCFullYear()                 + '-' +
 136                 padLeft(localDate.getUTCMonth()+1, 2, '0') + '-' +
 137                 padLeft(localDate.getUTCDate(),    2, '0');
 138         var localTimeStr = // e.g. '21:49:46'
 139                 padLeft(localDate.getUTCHours(),   2, '0') + ':' +
 140                 padLeft(localDate.getUTCMinutes(), 2, '0') + ':' +
 141                 padLeft(localDate.getUTCSeconds(), 2, '0');
 142
 143         return localDateStr + ' ' + localTimeStr + ' ' + timezoneInfo;
 144 }
 145
 146 /**
 147  * return date in local time formatted in rfc-2822 format
 148  * e.g. 'Thu, 21 Dec 2000 16:01:07 +0200'
 149  *
 150  * @param {Number} epoch: seconds since '00:00:00 1970-01-01 UTC'
 151  * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
 152  * @param {Boolean} [padDay] e.g. 'Sun, 07 Aug' if true, 'Sun, 7 Aug' otherwise
 153  * @returns {String} date in local time in rfc-2822 format
 154  */
 155 function formatDateRFC2882(epoch, timezoneInfo, padDay) {
 156         // A short textual representation of a month, three letters
 157         var months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
 158         // A textual representation of a day, three letters
 159         var days = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];
 160         // date corrected by timezone
 161         var localDate = new Date(1000 * (epoch +
 162                 timezoneOffset(timezoneInfo)));
 163         var localDateStr = // e.g. 'Sun, 7 Aug 2005' or 'Sun, 07 Aug 2005'
 164                 days[localDate.getUTCDay()] + ', ' +
 165                 (padDay ? padLeft(localDate.getUTCDate(),2,'0') : localDate.getUTCDate()) + ' ' +
 166                 months[localDate.getUTCMonth()] + ' ' +
 167                 localDate.getUTCFullYear();
 168         var localTimeStr = // e.g. '21:49:46'
 169                 padLeft(localDate.getUTCHours(),   2, '0') + ':' +
 170                 padLeft(localDate.getUTCMinutes(), 2, '0') + ':' +
 171                 padLeft(localDate.getUTCSeconds(), 2, '0');
 172
 173         return localDateStr + ' ' + localTimeStr + ' ' + timezoneInfo;
 174 }
 175
 176 /* end of datetime.js */