1 (function ($) {

     2 

     3 /**

     4  * Set the client's system time zone as default values of form fields.

     5  */

     6 Drupal.behaviors.setTimezone = {

     7   attach: function (context, settings) {

     8     $('select.timezone-detect', context).once('timezone', function () {

     9       var dateString = Date();

    10       // In some client environments, date strings include a time zone

    11       // abbreviation, between 3 and 5 letters enclosed in parentheses,

    12       // which can be interpreted by PHP.

    13       var matches = dateString.match(/\(([A-Z]{3,5})\)/);

    14       var abbreviation = matches ? matches[1] : 0;

    15 

    16       // For all other client environments, the abbreviation is set to "0"

    17       // and the current offset from UTC and daylight saving time status are

    18       // used to guess the time zone.

    19       var dateNow = new Date();

    20       var offsetNow = dateNow.getTimezoneOffset() * -60;

    21 

    22       // Use January 1 and July 1 as test dates for determining daylight

    23       // saving time status by comparing their offsets.

    24       var dateJan = new Date(dateNow.getFullYear(), 0, 1, 12, 0, 0, 0);

    25       var dateJul = new Date(dateNow.getFullYear(), 6, 1, 12, 0, 0, 0);

    26       var offsetJan = dateJan.getTimezoneOffset() * -60;

    27       var offsetJul = dateJul.getTimezoneOffset() * -60;

    28 

    29       var isDaylightSavingTime;

    30       // If the offset from UTC is identical on January 1 and July 1,

    31       // assume daylight saving time is not used in this time zone.

    32       if (offsetJan == offsetJul) {

    33         isDaylightSavingTime = '';

    34       }

    35       // If the maximum annual offset is equivalent to the current offset,

    36       // assume daylight saving time is in effect.

    37       else if (Math.max(offsetJan, offsetJul) == offsetNow) {

    38         isDaylightSavingTime = 1;

    39       }

    40       // Otherwise, assume daylight saving time is not in effect.

    41       else {

    42         isDaylightSavingTime = 0;

    43       }

    44 

    45       // Submit request to the system/timezone callback and set the form field

    46       // to the response time zone. The client date is passed to the callback

    47       // for debugging purposes. Submit a synchronous request to avoid database

    48       // errors associated with concurrent requests during install.

    49       var path = 'system/timezone/' + abbreviation + '/' + offsetNow + '/' + isDaylightSavingTime;

    50       var element = this;

    51       $.ajax({

    52         async: false,

    53         url: settings.basePath,

    54         data: { q: path, date: dateString },

    55         dataType: 'json',

    56         success: function (data) {

    57           if (data) {

    58             $(element).val(data);

    59           }

    60         }

    61       });

    62     });

    63   }

    64 };

    65 

    66 })(jQuery);