###########
Date Helper
###########
The Date Helper file contains functions that help you work with dates.
.. contents::
:local:
.. raw:: html
Loading this Helper
===================
This helper is loaded using the following code::
$this->load->helper('date');
Available Functions
===================
The following functions are available:
.. php:function:: now([$timezone = NULL])
:param string $timezone: Timezone
:returns: UNIX timestamp
:rtype: int
Returns the current time as a UNIX timestamp, referenced either to your server's
local time or any PHP suported timezone, based on the "time reference" setting
in your config file. If you do not intend to set your master time reference to
any other PHP supported timezone (which you'll typically do if you run a site
that lets each user set their own timezone settings) there is no benefit to using
this function over PHP's ``time()`` function.
::
echo now('Australia/Victoria');
If a timezone is not provided, it will return ``time()`` based on the
**time_reference** setting.
.. php:function:: mdate([$datestr = ''[, $time = '']])
:param string $datestr: Date string
:param int $time: UNIX timestamp
:returns: MySQL-formatted date
:rtype: string
This function is identical to PHP's `date() `_
function, except that it lets you use MySQL style date codes, where each
code letter is preceded with a percent sign, e.g. `%Y %m %d`
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::
$datestring = 'Year: %Y Month: %m Day: %d - %h:%i %a';
$time = time();
echo mdate($datestring, $time);
If a timestamp is not included in the second parameter the current time
will be used.
.. php:function:: standard_date([$fmt = 'DATE_RFC822'[, $time = NULL]])
:param string $fmt: Date format
:param int $time: UNIX timestamp
:returns: Formatted date or FALSE on invalid format
:rtype: string
Lets you generate a date string in one of several standardized formats.
Example::
$format = 'DATE_RFC822';
$time = time();
echo standard_date($format, $time);
.. note:: This function is DEPRECATED. Use the native ``date()`` combined with
`DateTime's format constants
`_
instead::
echo date(DATE_RFC822, time());
**Supported formats:**
=============== ======================= ======================================
Constant Description Example
=============== ======================= ======================================
DATE_ATOM Atom 2005-08-15T16:13:03+0000
DATE_COOKIE HTTP Cookies Sun, 14 Aug 2005 16:13:03 UTC
DATE_ISO8601 ISO-8601 2005-08-14T16:13:03+00:00
DATE_RFC822 RFC 822 Sun, 14 Aug 05 16:13:03 UTC
DATE_RFC850 RFC 850 Sunday, 14-Aug-05 16:13:03 UTC
DATE_RFC1036 RFC 1036 Sunday, 14-Aug-05 16:13:03 UTC
DATE_RFC1123 RFC 1123 Sun, 14 Aug 2005 16:13:03 UTC
DATE_RFC2822 RFC 2822 Sun, 14 Aug 2005 16:13:03 +0000
DATE_RSS RSS Sun, 14 Aug 2005 16:13:03 UTC
DATE_W3C W3C 2005-08-14T16:13:03+0000
=============== ======================= ======================================
.. php:function:: local_to_gmt([$time = ''])
:param int $time: UNIX timestamp
:returns: UNIX timestamp
:rtype: int
Takes a UNIX timestamp as input and returns it as GMT.
Example::
$gmt = local_to_gmt(time());
.. php:function:: gmt_to_local([$time = ''[, $timezone = 'UTC'[, $dst = FALSE]]])
:param int $time: UNIX timestamp
:param string $timezone: Timezone
:param bool $dst: Whether DST is active
:returns: UNIX timestamp
:rtype: int
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.
Example::
$timestamp = 1140153693;
$timezone = 'UM8';
$daylight_saving = TRUE;
echo gmt_to_local($timestamp, $timezone, $daylight_saving);
.. note:: For a list of timezones see the reference at the bottom of this page.
.. php:function:: mysql_to_unix([$time = ''])
:param string $time: MySQL timestamp
:returns: UNIX timestamp
:rtype: int
Takes a MySQL Timestamp as input and returns it as a UNIX timestamp.
Example::
$unix = mysql_to_unix('20061124092345');
.. php:function:: unix_to_human([$time = ''[, $seconds = FALSE[, $fmt = 'us']]])
:param int $time: UNIX timestamp
:param bool $seconds: Whether to show seconds
:param string $fmt: format (us or euro)
:returns: Formatted date
:rtype: string
Takes a UNIX timestamp as input and returns it in a human readable
format with this prototype::
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
.. php:function:: human_to_unix([$datestr = ''])
:param int $datestr: Date string
:returns: UNIX timestamp or FALSE on failure
:rtype: int
The opposite of the :php:func:`unix_to_time()` function. Takes a "human"
time as input and returns it as a UNIX timestamp. This is useful if you
accept "human" formatted dates submitted via a form. Returns boolean FALSE
date string passed to it is not formatted as indicated above.
Example::
$now = time();
$human = unix_to_human($now);
$unix = human_to_unix($human);
.. php:function:: nice_date([$bad_date = ''[, $format = FALSE]])
:param int $bad_date: The terribly formatted date-like string
:param string $format: Date format to return (same as PHP's ``date()`` function)
:returns: Formatted date
:rtype: string
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.
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');
.. php:function:: timespan([$seconds = 1[, $time = ''[, $units = '']]])
:param int $seconds: Number of seconds
:param string $time: UNIX timestamp
:param int $units: Number of time units to display
:returns: Formatted time difference
:rtype: string
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.
The thirdparameter is optional and limits the number of time units to display.
If the second parameter empty, the current time will be used.
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.
Example::
$post_date = '1079621429';
$now = time();
$units = 2;
echo timespan($post_date, $now, $units);
.. note:: The text generated by this function is found in the following language
file: `language//date_lang.php`
.. php:function:: days_in_month([$month = 0[, $year = '']])
:param int $month: a numeric month
:param int $year: a numeric year
:returns: Count of days in the specified month
:rtype: int
Returns the number of days in a given month/year. Takes leap years into
account.
Example::
echo days_in_month(06, 2005);
If the second parameter is empty, the current year will be used.
.. note:: This function will alias the native ``cal_days_in_month()``, if
it is available.
.. php:function:: date_range([$unix_start = ''[, $mixed = ''[, $is_unix = TRUE[, $format = 'Y-m-d']]]])
:param int $unix_start: UNIX timestamp of the range start date
:param int $mixed: UNIX timestamp of the range end date or interval in days
:param bool $is_unix: set to FALSE if $mixed is not a timestamp
:param string $format: Output date format, same as in ``date()``
:returns: An array of dates
:rtype: array
Returns a list of dates within a specified period.
Example::
$range = date_range('2012-01-01', '2012-01-15');
echo "First 15 days of 2012:";
foreach ($range as $date)
{
echo $date."\n";
}
.. php:function:: timezones([$tz = ''])
:param string $tz: A numeric timezone
:returns: Hour difference from UTC
:rtype: int
Takes a timezone reference (for a list of valid timezones, see the
"Timezone Reference" below) and returns the number of hours offset from
UTC.
Example::
echo timezones('UM5');
This function is useful when used with :php:func:`timezone_menu()`.
.. php:function:: timezone_menu([$default = 'UTC'[, $class = ''[, $name = 'timezones'[, $attributes = '']]]])
:param string $default: Timezone
:param string $class: Class name
:param string $name: Menu name
:param mixed $attributes: HTML attributes
:returns: HTML drop down menu with time zones
:rtype: string
Generates a pull-down menu of timezones, like this one:
.. raw:: html
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::
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//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
=========== =====================================================================
UM12 (UTC - 12:00) Baker/Howland Island
UM11 (UTC - 11:00) Samoa Time Zone, Niue
UM10 (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
UM1 (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) Srednekolymsk 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
UP13 (UTC +13:00) Phoenix Islands Time, Tonga
UP14 (UTC +14:00) Line Islands
=========== =====================================================================