[feature/new-tz-handling] Add function to update the timezone

PHPBB3-9558

phpBB/install/database_update.php

@@ -809,6 +809,105 @@ function _add_modules($modules_to_install)
 	$_module->remove_cache_file();
 }
 
+/**
+* Determinate the new timezone for a given phpBB 3.0 timezone and
+* "Daylight Saving Time" option
+*
+*	@param	$timezone	float	Users timezone in 3.0
+*	@param	$dst		int		Users daylight saving time
+*	@return		string		Users new php Timezone which is used since 3.1
+*/
+function _convert_phpbb30_timezone($timezone, $dst)
+{
+	$offset = $timezone + $dst;
+
+	switch ($timezone)
+	{
+		case '-12':
+			return 'Etc/GMT' . $offset;		//'[UTC - 12] Baker Island Time'
+		case '-11':
+			return 'Etc/GMT' . $offset;		//'[UTC - 11] Niue Time, Samoa Standard Time'
+		case '-10':
+			return 'Etc/GMT' . $offset;		//'[UTC - 10] Hawaii-Aleutian Standard Time, Cook Island Time'
+		case '-9.5':
+			return 'Pacific/Marquesas';		//'[UTC - 9:30] Marquesas Islands Time'
+		case '-9':
+			return 'Etc/GMT' . $offset;		//'[UTC - 9] Alaska Standard Time, Gambier Island Time'
+		case '-8':
+			return 'Etc/GMT' . $offset;		//'[UTC - 8] Pacific Standard Time'
+		case '-7':
+			return 'Etc/GMT' . $offset;		//'[UTC - 7] Mountain Standard Time'
+		case '-6':
+			return 'Etc/GMT' . $offset;		//'[UTC - 6] Central Standard Time'
+		case '-5':
+			return 'Etc/GMT' . $offset;		//'[UTC - 5] Eastern Standard Time'
+		case '-4.5':
+			return 'America/Caracas';		//'[UTC - 4:30] Venezuelan Standard Time'
+		case '-4':
+			return 'Etc/GMT' . $offset;		//'[UTC - 4] Atlantic Standard Time'
+		case '-3.5':
+			return 'America/St_Johns';		//'[UTC - 3:30] Newfoundland Standard Time'
+		case '-3':
+			return 'Etc/GMT' . $offset;		//'[UTC - 3] Amazon Standard Time, Central Greenland Time'
+		case '-2':
+			return 'Etc/GMT' . $offset;		//'[UTC - 2] Fernando de Noronha Time, South Georgia & the South Sandwich Islands Time'
+		case '-1':
+			return 'Etc/GMT' . $offset;		//'[UTC - 1] Azores Standard Time, Cape Verde Time, Eastern Greenland Time'
+		case '0':
+			return (!$dst) ? 'UTC' : 'Etc/GMT+1';		//'[UTC] Western European Time, Greenwich Mean Time'
+		case '1':
+			return 'Etc/GMT+' . $offset;	//'[UTC + 1] Central European Time, West African Time'
+		case '2':
+			return 'Etc/GMT+' . $offset;	//'[UTC + 2] Eastern European Time, Central African Time'
+		case '3':
+			return 'Etc/GMT+' . $offset;	//'[UTC + 3] Moscow Standard Time, Eastern African Time'
+		case '3.5':
+			return 'Asia/Tehran';			//'[UTC + 3:30] Iran Standard Time'
+		case '4':
+			return 'Etc/GMT+' . $offset;	//'[UTC + 4] Gulf Standard Time, Samara Standard Time'
+		case '4.5':
+			return 'Asia/Kabul';			//'[UTC + 4:30] Afghanistan Time'
+		case '5':
+			return 'Etc/GMT+' . $offset;	//'[UTC + 5] Pakistan Standard Time, Yekaterinburg Standard Time'
+		case '5.5':
+			return 'Asia/Kolkata';			//'[UTC + 5:30] Indian Standard Time, Sri Lanka Time'
+		case '5.75':
+			return 'Asia/Kathmandu';		//'[UTC + 5:45] Nepal Time'
+		case '6':
+			return 'Etc/GMT+' . $offset;	//'[UTC + 6] Bangladesh Time, Bhutan Time, Novosibirsk Standard Time'
+		case '6.5':
+			return 'Indian/Cocos';			//'[UTC + 6:30] Cocos Islands Time, Myanmar Time'
+		case '7':
+			return 'Etc/GMT+' . $offset;	//'[UTC + 7] Indochina Time, Krasnoyarsk Standard Time'
+		case '8':
+			return 'Etc/GMT+' . $offset;	//'[UTC + 8] Chinese Standard Time, Australian Western Standard Time, Irkutsk Standard Time'
+		case '8.75':
+			return 'Australia/Eucla';		//'[UTC + 8:45] Southeastern Western Australia Standard Time'
+		case '9':
+			return 'Etc/GMT+' . $offset;	//'[UTC + 9] Japan Standard Time, Korea Standard Time, Chita Standard Time'
+		case '9.5':
+			return 'Australia/ACT';			//'[UTC + 9:30] Australian Central Standard Time'
+		case '10':
+			return 'Etc/GMT+' . $offset;	//'[UTC + 10] Australian Eastern Standard Time, Vladivostok Standard Time'
+		case '10.5':
+			return 'Australia/Lord_Howe';	//'[UTC + 10:30] Lord Howe Standard Time'
+		case '11':
+			return 'Etc/GMT+' . $offset;	//'[UTC + 11] Solomon Island Time, Magadan Standard Time'
+		case '11.5':
+			return 'Pacific/Norfolk';		//'[UTC + 11:30] Norfolk Island Time'
+		case '12':
+			return 'Etc/GMT+12';			//'[UTC + 12] New Zealand Time, Fiji Time, Kamchatka Standard Time'
+		case '12.75':
+			return 'Pacific/Chatham';		//'[UTC + 12:45] Chatham Islands Time'
+		case '13':
+			return 'Pacific/Tongatapu';		//'[UTC + 13] Tonga Time, Phoenix Islands Time'
+		case '14':
+			return 'Pacific/Kiritimati';	//'[UTC + 14] Line Island Time'
+		default:
+			return 'UTC';
+	}
+}
+
 /****************************************************************************
 * ADD YOUR DATABASE SCHEMA CHANGES HERE										*
 *****************************************************************************/