user_guide_src/source/helpers/date_helper.rst - code-igniter-v3-giggi - Gitiles

 ###########
 Date Helper
 ###########

 The Date Helper file contains functions that help you work with dates.

 .. contents:: Page Contents

 Loading this Helper
 ===================

 This helper is loaded using the following code

 ::

 	$this->load->helper('date');

 The following functions are available:

 now()
 =====

 Returns the current time as a Unix timestamp, referenced either to your
 server's local time or any PHP suported timezone, based on the "time reference"
 setting in your config file. If you do not intend to set your master time reference
 to any other PHP suported timezone (which you'll typically do if you run a site that
 lets each user set their own timezone settings) there is no benefit to using this
 function over PHP's time() function.

 .. php:method:: now($timezone = NULL)

 	:param string 	$timezone: The timezone you want to be returned
 	:returns: integer

 ::
 	echo now("Australia/Victoria");

 If a timezone is not provided, it will return time() based on "time_reference" setting.

 mdate()
 =======

 This function is identical to PHP's `date() <http://www.php.net/date>`_
 function, except that it lets you use MySQL style date codes, where each
 code letter is preceded with a percent sign: %Y %m %d etc.

 The benefit of doing dates this way is that you don't have to worry
 about escaping any characters that are not date codes, as you would
 normally have to do with the date() function. Example

 .. php:method:: mdate($datestr = '', $time = '')

 	:param string 	$datestr: Date String
 	:param integer 	$time: time
 	:returns: integer


 ::

 	$datestring = "Year: %Y Month: %m Day: %d - %h:%i %a";
 	$time = time();
 	echo mdate($datestring, $time);

 If a timestamp is not included in the second parameter the current time
 will be used.

 standard_date()
 ===============

 Lets you generate a date string in one of several standardized formats.
 Example

 .. php:method:: standard_date($fmt = 'DATE_RFC822', $time = '')

 	:param string 	$fmt: the chosen format
 	:param string 	$time: Unix timestamp
 	:returns: string

 ::

 	$format = 'DATE_RFC822';
 	$time = time();
 	echo standard_date($format, $time);

 The first parameter must contain the format, the second parameter must
 contain the date as a Unix timestamp.

 .. note:: This function is DEPRECATED. Use the native ``date()`` combined
 	with `DateTime's format constants <http://www.php.net/manual/en/class.datetime.php#datetime.constants.types>`_
 	instead:

 	|
 	| echo date(DATE_RFC822, time());

 Supported formats:

 ===============	=======================	======================================
 Constant		Description				Example
 ===============	=======================	======================================
 DATE_ATOM	Atom			2005-08-15T16:13:03+0000
 DATE_COOKIE	HTTP Cookies		Sun, 14 Aug 2005 16:13:03 UTC
 DATE_ISO8601   	ISO-8601		2005-08-14T16:13:03+00:00
 DATE_RFC822	RFC 822			Sun, 14 Aug 05 16:13:03 UTC
 DATE_RFC850	RFC 850			Sunday, 14-Aug-05 16:13:03 UTC
 DATE_RFC1036	RFC 1036		Sunday, 14-Aug-05 16:13:03 UTC
 DATE_RFC1123	RFC 1123		Sun, 14 Aug 2005 16:13:03 UTC
 DATE_RFC2822 	RFC 2822		Sun, 14 Aug 2005 16:13:03 +0000
 DATE_RSS	RSS			Sun, 14 Aug 2005 16:13:03 UTC
 DATE_W3C	W3C			2005-08-14T16:13:03+0000
 ===============	=======================	======================================

 local_to_gmt()
 ==============

 Takes a Unix timestamp as input and returns it as GMT.

 .. php:method:: local_to_gmt($time = '')

 	:param integer 	$time: Unix timestamp
 	:returns: string

 Example:

 ::

 	$now = time();
 	$gmt = local_to_gmt($now);

 gmt_to_local()
 ==============

 Takes a Unix timestamp (referenced to GMT) as input, and converts it to
 a localized timestamp based on the timezone and Daylight Saving time
 submitted.

 .. php:method:: gmt_to_local($time = '', $timezone = 'UTC', $dst = FALSE)

 	:param integer 	$time: Unix timestamp
 	:param string 	$timezone: timezone
 	:param boolean 	$dst: whether DST is active
 	:returns: integer

 Example

 ::

 	$timestamp = '1140153693';
 	$timezone  = 'UM8';
 	$daylight_saving = TRUE;
 	echo gmt_to_local($timestamp, $timezone, $daylight_saving);


 .. note:: For a list of timezones see the reference at the bottom of this page.


 mysql_to_unix()
 ===============

 Takes a MySQL Timestamp as input and returns it as Unix.

 .. php:method:: mysql_to_unix($time = '')

 	:param integer 	$time: Unix timestamp
 	:returns: integer

 Example

 ::

 	$mysql = '20061124092345';
 	$unix = mysql_to_unix($mysql);

 unix_to_human()
 ===============

 Takes a Unix timestamp as input and returns it in a human readable
 format with this prototype

 .. php:method:: unix_to_human($time = '', $seconds = FALSE, $fmt = 'us')

 	:param integer 	$time: Unix timestamp
 	:param boolean 	$seconds: whether to show seconds
 	:param string 	$fmt: format: us or euro
 	:returns: integer

 Example

 ::

 	YYYY-MM-DD HH:MM:SS AM/PM

 This can be useful if you need to display a date in a form field for
 submission.

 The time can be formatted with or without seconds, and it can be set to
 European or US format. If only the timestamp is submitted it will return
 the time without seconds formatted for the U.S. Examples

 ::

 	$now = time();
 	echo unix_to_human($now); // U.S. time, no seconds
 	echo unix_to_human($now, TRUE, 'us'); // U.S. time with seconds
 	echo unix_to_human($now, TRUE, 'eu'); // Euro time with seconds

 human_to_unix()
 ===============

 The opposite of the above function. Takes a "human" time as input and
 returns it as Unix. This function is useful if you accept "human"
 formatted dates submitted via a form. Returns FALSE (boolean) if the
 date string passed to it is not formatted as indicated above.

 .. php:method:: human_to_unix($datestr = '')

 	:param integer 	$datestr: Date String
 	:returns: integer

 Example:

 ::

 	$now = time();
 	$human = unix_to_human($now);
 	$unix = human_to_unix($human);

 nice_date()
 ===========

 This function can take a number poorly-formed date formats and convert
 them into something useful. It also accepts well-formed dates.

 The function will return a Unix timestamp by default. You can,
 optionally, pass a format string (the same type as the PHP date function
 accepts) as the second parameter.

 .. php:method:: nice_date($bad_date = '', $format = FALSE)

 	:param integer 	$bad_date: The terribly formatted date-like string
 	:param string 	$format: Date format to return (same as php date function)
 	:returns: string

 Example

 ::

 	$bad_date = '199605';
 	// Should Produce: 1996-05-01
 	$better_date = nice_date($bad_date, 'Y-m-d');

 	$bad_date = '9-11-2001';
 	// Should Produce: 2001-09-11
 	$better_date = nice_date($bad_date, 'Y-m-d');

 timespan()
 ==========

 Formats a unix timestamp so that is appears similar to this
 ::

 	1 Year, 10 Months, 2 Weeks, 5 Days, 10 Hours, 16 Minutes

 The first parameter must contain a Unix timestamp. The second parameter
 must contain a timestamp that is greater that the first timestamp. If
 the second parameter empty, the current time will be used. The third
 parameter is optional and limits the number of time units to display.
 The most common purpose for this function is to show how much time has
 elapsed from some point in time in the past to now.

 .. php:method:: timespan($seconds = 1, $time = '', $units = '')

 	:param integer 	$seconds: a number of seconds
 	:param string 	$time: Unix timestamp
 	:param integer 	$units: a number of time units to display
 	:returns: string

 Example

 ::

 	$post_date = '1079621429';
 	$now = time();
 	$units = 2;
 	echo timespan($post_date, $now, $units);

 .. note:: The text generated by this function is found in the following language
 	file: language/<your_lang>/date_lang.php

 days_in_month()
 ===============

 Returns the number of days in a given month/year. Takes leap years into
 account.

 .. php:method:: days_in_month($month = 0, $year = '')

 	:param integer 	$month: a numeric month
 	:param integer 	$year: a numeric year
 	:returns: integer

 Example

 ::

 	echo days_in_month(06, 2005);

 If the second parameter is empty, the current year will be used.

 timezones()
 ===========

 Takes a timezone reference (for a list of valid timezones, see the
 "Timezone Reference" below) and returns the number of hours offset from
 UTC.

 .. php:method:: timezones($tz = '')

 	:param string 	$tz: a numeric timezone
 	:returns: string

 Example

 ::

 	echo timezones('UM5');


 This function is useful when used with `timezone_menu()`.

 timezone_menu()
 ===============

 Generates a pull-down menu of timezones, like this one:


 .. raw:: html

 	<form action="#">
 		<select name="timezones">
 			<option value='UM12'>(UTC -12:00) Baker/Howland Island</option>
 			<option value='UM11'>(UTC -11:00) Samoa Time Zone, Niue</option>
 			<option value='UM10'>(UTC -10:00) Hawaii-Aleutian Standard Time, Cook Islands, Tahiti</option>
 			<option value='UM95'>(UTC -9:30) Marquesas Islands</option>
 			<option value='UM9'>(UTC -9:00) Alaska Standard Time, Gambier Islands</option>
 			<option value='UM8'>(UTC -8:00) Pacific Standard Time, Clipperton Island</option>
 			<option value='UM7'>(UTC -7:00) Mountain Standard Time</option>
 			<option value='UM6'>(UTC -6:00) Central Standard Time</option>
 			<option value='UM5'>(UTC -5:00) Eastern Standard Time, Western Caribbean Standard Time</option>
 			<option value='UM45'>(UTC -4:30) Venezuelan Standard Time</option>
 			<option value='UM4'>(UTC -4:00) Atlantic Standard Time, Eastern Caribbean Standard Time</option>
 			<option value='UM35'>(UTC -3:30) Newfoundland Standard Time</option>
 			<option value='UM3'>(UTC -3:00) Argentina, Brazil, French Guiana, Uruguay</option>
 			<option value='UM2'>(UTC -2:00) South Georgia/South Sandwich Islands</option>
 			<option value='UM1'>(UTC -1:00) Azores, Cape Verde Islands</option>
 			<option value='UTC' selected='selected'>(UTC) Greenwich Mean Time, Western European Time</option>
 			<option value='UP1'>(UTC +1:00) Central European Time, West Africa Time</option>
 			<option value='UP2'>(UTC +2:00) Central Africa Time, Eastern European Time, Kaliningrad Time</option>
 			<option value='UP3'>(UTC +3:00) Moscow Time, East Africa Time</option>
 			<option value='UP35'>(UTC +3:30) Iran Standard Time</option>
 			<option value='UP4'>(UTC +4:00) Azerbaijan Standard Time, Samara Time</option>
 			<option value='UP45'>(UTC +4:30) Afghanistan</option>
 			<option value='UP5'>(UTC +5:00) Pakistan Standard Time, Yekaterinburg Time</option>
 			<option value='UP55'>(UTC +5:30) Indian Standard Time, Sri Lanka Time</option>
 			<option value='UP575'>(UTC +5:45) Nepal Time</option>
 			<option value='UP6'>(UTC +6:00) Bangladesh Standard Time, Bhutan Time, Omsk Time</option>
 			<option value='UP65'>(UTC +6:30) Cocos Islands, Myanmar</option>
 			<option value='UP7'>(UTC +7:00) Krasnoyarsk Time, Cambodia, Laos, Thailand, Vietnam</option>
 			<option value='UP8'>(UTC +8:00) Australian Western Standard Time, Beijing Time, Irkutsk Time</option>
 			<option value='UP875'>(UTC +8:45) Australian Central Western Standard Time</option>
 			<option value='UP9'>(UTC +9:00) Japan Standard Time, Korea Standard Time, Yakutsk Time</option>
 			<option value='UP95'>(UTC +9:30) Australian Central Standard Time</option>
 			<option value='UP10'>(UTC +10:00) Australian Eastern Standard Time, Vladivostok Time</option>
 			<option value='UP105'>(UTC +10:30) Lord Howe Island</option>
 			<option value='UP11'>(UTC +11:00) Magadan Time, Solomon Islands, Vanuatu</option>
 			<option value='UP115'>(UTC +11:30) Norfolk Island</option>
 			<option value='UP12'>(UTC +12:00) Fiji, Gilbert Islands, Kamchatka Time, New Zealand Standard Time</option>
 			<option value='UP1275'>(UTC +12:45) Chatham Islands Standard Time</option>
 			<option value='UP13'>(UTC +13:00) Phoenix Islands Time, Tonga</option>
 			<option value='UP14'>(UTC +14:00) Line Islands</option>
 		</select>
 	</form>


 This menu is useful if you run a membership site in which your users are
 allowed to set their local timezone value.

 The first parameter lets you set the "selected" state of the menu. For
 example, to set Pacific time as the default you will do this

 .. php:method:: timezone_menu($default = 'UTC', $class = '', $name = 'timezones', $attributes = '')

 	:param string 	$default: timezone
 	:param string	$class: classname
 	:param string	$name: menu name
 	:param mixed	$attributes: attributes
 	:returns: string

 Example:

 ::

 	echo timezone_menu('UM8');

 Please see the timezone reference below to see the values of this menu.

 The second parameter lets you set a CSS class name for the menu.

 The fourth parameter lets you set one or more attributes on the generated select tag.

 .. note:: The text contained in the menu is found in the following
 	language file: `language/<your_lang>/date_lang.php`


 Timezone Reference
 ==================

 The following table indicates each timezone and its location.

 Note some of the location lists have been abridged for clarity and formatting.

 ===========	=====================================================================
 Time Zone	Location
 ===========	=====================================================================
 UM2			(UTC - 12:00) Baker/Howland Island
 UM1			(UTC - 11:00) Samoa Time Zone, Niue
 UM0			(UTC - 10:00) Hawaii-Aleutian Standard Time, Cook Islands
 UM95		(UTC - 09:30) Marquesas Islands
 UM9			(UTC - 09:00) Alaska Standard Time, Gambier Islands
 UM8			(UTC - 08:00) Pacific Standard Time, Clipperton Island
 UM7			(UTC - 11:00) Mountain Standard Time
 UM6			(UTC - 06:00) Central Standard Time
 UM5			(UTC - 05:00) Eastern Standard Time, Western Caribbean
 UM45		(UTC - 04:30) Venezuelan Standard Time
 UM4			(UTC - 04:00) Atlantic Standard Time, Eastern Caribbean
 UM35		(UTC - 03:30) Newfoundland Standard Time
 UM3			(UTC - 03:00) Argentina, Brazil, French Guiana, Uruguay
 UM2			(UTC - 02:00) South Georgia/South Sandwich Islands
 UM			(UTC -1:00) Azores, Cape Verde Islands
 UTC			(UTC) Greenwich Mean Time, Western European Time
 UP1			(UTC +1:00) Central European Time, West Africa Time
 UP2			(UTC +2:00) Central Africa Time, Eastern European Time
 UP3			(UTC +3:00) Moscow Time, East Africa Time
 UP35		(UTC +3:30) Iran Standard Time
 UP4			(UTC +4:00) Azerbaijan Standard Time, Samara Time
 UP45		(UTC +4:30) Afghanistan
 UP5			(UTC +5:00) Pakistan Standard Time, Yekaterinburg Time
 UP55		(UTC +5:30) Indian Standard Time, Sri Lanka Time
 UP575		(UTC +5:45) Nepal Time
 UP6			(UTC +6:00) Bangladesh Standard Time, Bhutan Time, Omsk Time
 UP65		(UTC +6:30) Cocos Islands, Myanmar
 UP7			(UTC +7:00) Krasnoyarsk Time, Cambodia, Laos, Thailand, Vietnam
 UP8			(UTC +8:00) Australian Western Standard Time, Beijing Time
 UP875		(UTC +8:45) Australian Central Western Standard Time
 UP9			(UTC +9:00) Japan Standard Time, Korea Standard Time, Yakutsk
 UP95		(UTC +9:30) Australian Central Standard Time
 UP10		(UTC +10:00) Australian Eastern Standard Time, Vladivostok Time
 UP105		(UTC +10:30) Lord Howe Island
 UP11		(UTC +11:00) Magadan Time, Solomon Islands, Vanuatu
 UP115		(UTC +11:30) Norfolk Island
 UP12		(UTC +12:00) Fiji, Gilbert Islands, Kamchatka, New Zealand
 UP1275		(UTC +12:45) Chatham Islands Standard Time
 UP1			(UTC +13:00) Phoenix Islands Time, Tonga
 UP14		(UTC +14:00) Line Islands
 ===========	=====================================================================
	###########
	Date Helper
	###########

	The Date Helper file contains functions that help you work with dates.

	.. contents:: Page Contents

	Loading this Helper
	===================

	This helper is loaded using the following code

	::

	$this->load->helper('date');

	The following functions are available:

	now()
	=====

	Returns the current time as a Unix timestamp, referenced either to your
	server's local time or any PHP suported timezone, based on the "time reference"
	setting in your config file. If you do not intend to set your master time reference
	to any other PHP suported timezone (which you'll typically do if you run a site that
	lets each user set their own timezone settings) there is no benefit to using this
	function over PHP's time() function.

	.. php:method:: now($timezone = NULL)

	:param string $timezone: The timezone you want to be returned
	:returns: integer

	::
	echo now("Australia/Victoria");

	If a timezone is not provided, it will return time() based on "time_reference" setting.

	mdate()
	=======

	This function is identical to PHP's `date() <http://www.php.net/date>`_
	function, except that it lets you use MySQL style date codes, where each
	code letter is preceded with a percent sign: %Y %m %d etc.

	The benefit of doing dates this way is that you don't have to worry
	about escaping any characters that are not date codes, as you would
	normally have to do with the date() function. Example

	.. php:method:: mdate($datestr = '', $time = '')

	:param string $datestr: Date String
	:param integer $time: time
	:returns: integer


	::

	$datestring = "Year: %Y Month: %m Day: %d - %h:%i %a";
	$time = time();
	echo mdate($datestring, $time);

	If a timestamp is not included in the second parameter the current time
	will be used.

	standard_date()
	===============

	Lets you generate a date string in one of several standardized formats.
	Example

	.. php:method:: standard_date($fmt = 'DATE_RFC822', $time = '')

	:param string $fmt: the chosen format
	:param string $time: Unix timestamp
	:returns: string

	::

	$format = 'DATE_RFC822';
	$time = time();
	echo standard_date($format, $time);

	The first parameter must contain the format, the second parameter must
	contain the date as a Unix timestamp.

	.. note:: This function is DEPRECATED. Use the native ``date()`` combined
	with `DateTime's format constants <http://www.php.net/manual/en/class.datetime.php#datetime.constants.types>`_
	instead:

	\|
	\| echo date(DATE_RFC822, time());

	Supported formats:

	=============== ======================= ======================================
	Constant Description Example
	=============== ======================= ======================================
	DATE_ATOM Atom 2005-08-15T16:13:03+0000
	DATE_COOKIE HTTP Cookies Sun, 14 Aug 2005 16:13:03 UTC
	DATE_ISO8601 ISO-8601 2005-08-14T16:13:03+00:00
	DATE_RFC822 RFC 822 Sun, 14 Aug 05 16:13:03 UTC
	DATE_RFC850 RFC 850 Sunday, 14-Aug-05 16:13:03 UTC
	DATE_RFC1036 RFC 1036 Sunday, 14-Aug-05 16:13:03 UTC
	DATE_RFC1123 RFC 1123 Sun, 14 Aug 2005 16:13:03 UTC
	DATE_RFC2822 RFC 2822 Sun, 14 Aug 2005 16:13:03 +0000
	DATE_RSS RSS Sun, 14 Aug 2005 16:13:03 UTC
	DATE_W3C W3C 2005-08-14T16:13:03+0000
	=============== ======================= ======================================

	local_to_gmt()
	==============

	Takes a Unix timestamp as input and returns it as GMT.

	.. php:method:: local_to_gmt($time = '')

	:param integer $time: Unix timestamp
	:returns: string

	Example:

	::

	$now = time();
	$gmt = local_to_gmt($now);

	gmt_to_local()
	==============

	Takes a Unix timestamp (referenced to GMT) as input, and converts it to
	a localized timestamp based on the timezone and Daylight Saving time
	submitted.

	.. php:method:: gmt_to_local($time = '', $timezone = 'UTC', $dst = FALSE)

	:param integer $time: Unix timestamp
	:param string $timezone: timezone
	:param boolean $dst: whether DST is active
	:returns: integer

	Example

	::

	$timestamp = '1140153693';
	$timezone = 'UM8';
	$daylight_saving = TRUE;
	echo gmt_to_local($timestamp, $timezone, $daylight_saving);


	.. note:: For a list of timezones see the reference at the bottom of this page.


	mysql_to_unix()
	===============

	Takes a MySQL Timestamp as input and returns it as Unix.

	.. php:method:: mysql_to_unix($time = '')

	:param integer $time: Unix timestamp
	:returns: integer

	Example

	::

	$mysql = '20061124092345';
	$unix = mysql_to_unix($mysql);

	unix_to_human()
	===============

	Takes a Unix timestamp as input and returns it in a human readable
	format with this prototype

	.. php:method:: unix_to_human($time = '', $seconds = FALSE, $fmt = 'us')

	:param integer $time: Unix timestamp
	:param boolean $seconds: whether to show seconds
	:param string $fmt: format: us or euro
	:returns: integer

	Example

	::

	YYYY-MM-DD HH:MM:SS AM/PM

	This can be useful if you need to display a date in a form field for
	submission.

	The time can be formatted with or without seconds, and it can be set to
	European or US format. If only the timestamp is submitted it will return
	the time without seconds formatted for the U.S. Examples

	::

	$now = time();
	echo unix_to_human($now); // U.S. time, no seconds
	echo unix_to_human($now, TRUE, 'us'); // U.S. time with seconds
	echo unix_to_human($now, TRUE, 'eu'); // Euro time with seconds

	human_to_unix()
	===============

	The opposite of the above function. Takes a "human" time as input and
	returns it as Unix. This function is useful if you accept "human"
	formatted dates submitted via a form. Returns FALSE (boolean) if the
	date string passed to it is not formatted as indicated above.

	.. php:method:: human_to_unix($datestr = '')

	:param integer $datestr: Date String
	:returns: integer

	Example:

	::

	$now = time();
	$human = unix_to_human($now);
	$unix = human_to_unix($human);

	nice_date()
	===========

	This function can take a number poorly-formed date formats and convert
	them into something useful. It also accepts well-formed dates.

	The function will return a Unix timestamp by default. You can,
	optionally, pass a format string (the same type as the PHP date function
	accepts) as the second parameter.

	.. php:method:: nice_date($bad_date = '', $format = FALSE)

	:param integer $bad_date: The terribly formatted date-like string
	:param string $format: Date format to return (same as php date function)
	:returns: string

	Example

	::

	$bad_date = '199605';
	// Should Produce: 1996-05-01
	$better_date = nice_date($bad_date, 'Y-m-d');

	$bad_date = '9-11-2001';
	// Should Produce: 2001-09-11
	$better_date = nice_date($bad_date, 'Y-m-d');

	timespan()
	==========

	Formats a unix timestamp so that is appears similar to this
	::

	1 Year, 10 Months, 2 Weeks, 5 Days, 10 Hours, 16 Minutes

	The first parameter must contain a Unix timestamp. The second parameter
	must contain a timestamp that is greater that the first timestamp. If
	the second parameter empty, the current time will be used. The third
	parameter is optional and limits the number of time units to display.
	The most common purpose for this function is to show how much time has
	elapsed from some point in time in the past to now.

	.. php:method:: timespan($seconds = 1, $time = '', $units = '')

	:param integer $seconds: a number of seconds
	:param string $time: Unix timestamp
	:param integer $units: a number of time units to display
	:returns: string

	Example

	::

	$post_date = '1079621429';
	$now = time();
	$units = 2;
	echo timespan($post_date, $now, $units);

	.. note:: The text generated by this function is found in the following language
	file: language/<your_lang>/date_lang.php

	days_in_month()
	===============

	Returns the number of days in a given month/year. Takes leap years into
	account.

	.. php:method:: days_in_month($month = 0, $year = '')

	:param integer $month: a numeric month
	:param integer $year: a numeric year
	:returns: integer

	Example

	::

	echo days_in_month(06, 2005);

	If the second parameter is empty, the current year will be used.

	timezones()
	===========

	Takes a timezone reference (for a list of valid timezones, see the
	"Timezone Reference" below) and returns the number of hours offset from
	UTC.

	.. php:method:: timezones($tz = '')

	:param string $tz: a numeric timezone
	:returns: string

	Example

	::

	echo timezones('UM5');


	This function is useful when used with `timezone_menu()`.

	timezone_menu()
	===============

	Generates a pull-down menu of timezones, like this one:


	.. raw:: html

	<form action="#">
	<select name="timezones">
	<option value='UM12'>(UTC -12:00) Baker/Howland Island</option>
	<option value='UM11'>(UTC -11:00) Samoa Time Zone, Niue</option>
	<option value='UM10'>(UTC -10:00) Hawaii-Aleutian Standard Time, Cook Islands, Tahiti</option>
	<option value='UM95'>(UTC -9:30) Marquesas Islands</option>
	<option value='UM9'>(UTC -9:00) Alaska Standard Time, Gambier Islands</option>
	<option value='UM8'>(UTC -8:00) Pacific Standard Time, Clipperton Island</option>
	<option value='UM7'>(UTC -7:00) Mountain Standard Time</option>
	<option value='UM6'>(UTC -6:00) Central Standard Time</option>
	<option value='UM5'>(UTC -5:00) Eastern Standard Time, Western Caribbean Standard Time</option>
	<option value='UM45'>(UTC -4:30) Venezuelan Standard Time</option>
	<option value='UM4'>(UTC -4:00) Atlantic Standard Time, Eastern Caribbean Standard Time</option>
	<option value='UM35'>(UTC -3:30) Newfoundland Standard Time</option>
	<option value='UM3'>(UTC -3:00) Argentina, Brazil, French Guiana, Uruguay</option>
	<option value='UM2'>(UTC -2:00) South Georgia/South Sandwich Islands</option>
	<option value='UM1'>(UTC -1:00) Azores, Cape Verde Islands</option>
	<option value='UTC' selected='selected'>(UTC) Greenwich Mean Time, Western European Time</option>
	<option value='UP1'>(UTC +1:00) Central European Time, West Africa Time</option>
	<option value='UP2'>(UTC +2:00) Central Africa Time, Eastern European Time, Kaliningrad Time</option>
	<option value='UP3'>(UTC +3:00) Moscow Time, East Africa Time</option>
	<option value='UP35'>(UTC +3:30) Iran Standard Time</option>
	<option value='UP4'>(UTC +4:00) Azerbaijan Standard Time, Samara Time</option>
	<option value='UP45'>(UTC +4:30) Afghanistan</option>
	<option value='UP5'>(UTC +5:00) Pakistan Standard Time, Yekaterinburg Time</option>
	<option value='UP55'>(UTC +5:30) Indian Standard Time, Sri Lanka Time</option>
	<option value='UP575'>(UTC +5:45) Nepal Time</option>
	<option value='UP6'>(UTC +6:00) Bangladesh Standard Time, Bhutan Time, Omsk Time</option>
	<option value='UP65'>(UTC +6:30) Cocos Islands, Myanmar</option>
	<option value='UP7'>(UTC +7:00) Krasnoyarsk Time, Cambodia, Laos, Thailand, Vietnam</option>
	<option value='UP8'>(UTC +8:00) Australian Western Standard Time, Beijing Time, Irkutsk Time</option>
	<option value='UP875'>(UTC +8:45) Australian Central Western Standard Time</option>
	<option value='UP9'>(UTC +9:00) Japan Standard Time, Korea Standard Time, Yakutsk Time</option>
	<option value='UP95'>(UTC +9:30) Australian Central Standard Time</option>
	<option value='UP10'>(UTC +10:00) Australian Eastern Standard Time, Vladivostok Time</option>
	<option value='UP105'>(UTC +10:30) Lord Howe Island</option>
	<option value='UP11'>(UTC +11:00) Magadan Time, Solomon Islands, Vanuatu</option>
	<option value='UP115'>(UTC +11:30) Norfolk Island</option>
	<option value='UP12'>(UTC +12:00) Fiji, Gilbert Islands, Kamchatka Time, New Zealand Standard Time</option>
	<option value='UP1275'>(UTC +12:45) Chatham Islands Standard Time</option>
	<option value='UP13'>(UTC +13:00) Phoenix Islands Time, Tonga</option>
	<option value='UP14'>(UTC +14:00) Line Islands</option>
	</select>
	</form>


	This menu is useful if you run a membership site in which your users are
	allowed to set their local timezone value.

	The first parameter lets you set the "selected" state of the menu. For
	example, to set Pacific time as the default you will do this

	.. php:method:: timezone_menu($default = 'UTC', $class = '', $name = 'timezones', $attributes = '')

	:param string $default: timezone
	:param string $class: classname
	:param string $name: menu name
	:param mixed $attributes: attributes
	:returns: string

	Example:

	::

	echo timezone_menu('UM8');

	Please see the timezone reference below to see the values of this menu.

	The second parameter lets you set a CSS class name for the menu.

	The fourth parameter lets you set one or more attributes on the generated select tag.

	.. note:: The text contained in the menu is found in the following
	language file: `language/<your_lang>/date_lang.php`


	Timezone Reference
	==================

	The following table indicates each timezone and its location.

	Note some of the location lists have been abridged for clarity and formatting.

	=========== =====================================================================
	Time Zone Location
	=========== =====================================================================
	UM2 (UTC - 12:00) Baker/Howland Island
	UM1 (UTC - 11:00) Samoa Time Zone, Niue
	UM0 (UTC - 10:00) Hawaii-Aleutian Standard Time, Cook Islands
	UM95 (UTC - 09:30) Marquesas Islands
	UM9 (UTC - 09:00) Alaska Standard Time, Gambier Islands
	UM8 (UTC - 08:00) Pacific Standard Time, Clipperton Island
	UM7 (UTC - 11:00) Mountain Standard Time
	UM6 (UTC - 06:00) Central Standard Time
	UM5 (UTC - 05:00) Eastern Standard Time, Western Caribbean
	UM45 (UTC - 04:30) Venezuelan Standard Time
	UM4 (UTC - 04:00) Atlantic Standard Time, Eastern Caribbean
	UM35 (UTC - 03:30) Newfoundland Standard Time
	UM3 (UTC - 03:00) Argentina, Brazil, French Guiana, Uruguay
	UM2 (UTC - 02:00) South Georgia/South Sandwich Islands
	UM (UTC -1:00) Azores, Cape Verde Islands
	UTC (UTC) Greenwich Mean Time, Western European Time
	UP1 (UTC +1:00) Central European Time, West Africa Time
	UP2 (UTC +2:00) Central Africa Time, Eastern European Time
	UP3 (UTC +3:00) Moscow Time, East Africa Time
	UP35 (UTC +3:30) Iran Standard Time
	UP4 (UTC +4:00) Azerbaijan Standard Time, Samara Time
	UP45 (UTC +4:30) Afghanistan
	UP5 (UTC +5:00) Pakistan Standard Time, Yekaterinburg Time
	UP55 (UTC +5:30) Indian Standard Time, Sri Lanka Time
	UP575 (UTC +5:45) Nepal Time
	UP6 (UTC +6:00) Bangladesh Standard Time, Bhutan Time, Omsk Time
	UP65 (UTC +6:30) Cocos Islands, Myanmar
	UP7 (UTC +7:00) Krasnoyarsk Time, Cambodia, Laos, Thailand, Vietnam
	UP8 (UTC +8:00) Australian Western Standard Time, Beijing Time
	UP875 (UTC +8:45) Australian Central Western Standard Time
	UP9 (UTC +9:00) Japan Standard Time, Korea Standard Time, Yakutsk
	UP95 (UTC +9:30) Australian Central Standard Time
	UP10 (UTC +10:00) Australian Eastern Standard Time, Vladivostok Time
	UP105 (UTC +10:30) Lord Howe Island
	UP11 (UTC +11:00) Magadan Time, Solomon Islands, Vanuatu
	UP115 (UTC +11:30) Norfolk Island
	UP12 (UTC +12:00) Fiji, Gilbert Islands, Kamchatka, New Zealand
	UP1275 (UTC +12:45) Chatham Islands Standard Time
	UP1 (UTC +13:00) Phoenix Islands Time, Tonga
	UP14 (UTC +14:00) Line Islands
	=========== =====================================================================