/** * Set the client's system time zone as default values of form fields. */ Drupal.setDefaultTimezone = function() { var dateString = Date(); // In some client environments, date strings include a time zone // abbreviation which can be interpreted by PHP. var matches = Date().match(/\(([A-Z]{3,5})\)/); var abbreviation = matches ? matches[1] : 0; // For all other client environments, the abbreviation is set to "0" // and the current offset from UTC and daylight saving time status are // used to guess the time zone. var dateNow = new Date(); var offsetNow = dateNow.getTimezoneOffset() * -60; // Use January 1 and July 1 as test dates for determining daylight // saving time status by comparing their offsets. var dateJan = new Date(dateNow.getFullYear(), 0, 1, 12, 0, 0, 0); var dateJul = new Date(dateNow.getFullYear(), 6, 1, 12, 0, 0, 0); var offsetJan = dateJan.getTimezoneOffset() * -60; var offsetJul = dateJul.getTimezoneOffset() * -60; // If the offset from UTC is identical on January 1 and July 1, // assume daylight saving time is not used in this time zone. if (offsetJan == offsetJul) { var isDaylightSavingTime = ''; } // If the maximum annual offset is equivalent to the current offset, // assume daylight saving time is in effect. else if (Math.max(offsetJan, offsetJul) == offsetNow) { var isDaylightSavingTime = 1; } // Otherwise, assume daylight saving time is not in effect. else { var isDaylightSavingTime = 0; } // Submit request to the user/timezone callback and set the form field // to the response time zone. var path = 'user/timezone/' + abbreviation + '/' + offsetNow + '/' + isDaylightSavingTime; $.getJSON(Drupal.settings.basePath, { q: path, date: dateString }, function (data) { if (data) { $("#edit-date-default-timezone, #edit-user-register-timezone, #edit-timezone-name").val(data); } }); };