# Date Helper

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

- Loading this Helper
- Available Functions
- Timezone Reference

## Loading this Helper

This helper is loaded using the following code:

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

## Available Functions

The following functions are available:

`now`([$timezone = NULL])

  Parameters: |
  - $timezone (string) – Timezone
  Returns: | UNIX timestamp
  Return type: | int

  Returns the current time as a UNIX timestamp, referenced either to your server’s local time or any PHP supported 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.

`mdate`([$datestr = ''[, $time = '']])

  Parameters: |
  - $datestr (string) – Date string
  - $time (int) – UNIX timestamp
  Returns: | MySQL-formatted date
  Return type: | 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.

`standard_date`([$fmt = 'DATE_RFC822'[, $time = NULL]])

  Parameters: |
  - $fmt (string) – Date format
  - $time (int) – UNIX timestamp
  Returns: | Formatted date or FALSE on invalid format
  Return type: | 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

`local_to_gmt`([$time = ''])

  Parameters: |
  - $time (int) – UNIX timestamp
  Returns: | UNIX timestamp
  Return type: | int

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

  Example:

      $gmt = local_to_gmt(time());

`gmt_to_local`([$time = ''[, $timezone = 'UTC'[, $dst = FALSE]]])

  Parameters: |
  - $time (int) – UNIX timestamp
  - $timezone (string) – Timezone
  - $dst (bool) – Whether DST is active
  Returns: | UNIX timestamp
  Return type: | 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.

`mysql_to_unix`([$time = ''])

  Parameters: |
  - $time (string) – MySQL timestamp
  Returns: | UNIX timestamp
  Return type: | int

  Takes a MySQL Timestamp as input and returns it as a UNIX timestamp.

  Example:

      $unix = mysql_to_unix('20061124092345');

`unix_to_human`([$time = ''[, $seconds = FALSE[, $fmt = 'us']]])

  Parameters: |
  - $time (int) – UNIX timestamp
  - $seconds (bool) – Whether to show seconds
  - $fmt (string) – format (us or euro)
  Returns: | Formatted date
  Return type: | 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

`human_to_unix`([$datestr = ''])

  Parameters: |
  - $datestr (int) – Date string
  Returns: | UNIX timestamp or FALSE on failure
  Return type: | int

  The opposite of the `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);

`nice_date`([$bad_date = ''[, $format = FALSE]])

  Parameters: |
  - $bad_date (int) – The terribly formatted date-like string
  - $format (string) – Date format to return (same as PHP’s `date()` function)
  Returns: | Formatted date
  Return type: | 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');

  Note

  This function is DEPRECATED. Use PHP’s native DateTime class instead.

`timespan`([$seconds = 1[, $time = ''[, $units = '']]])

  Parameters: |
  - $seconds (int) – Number of seconds
  - $time (string) – UNIX timestamp
  - $units (int) – Number of time units to display
  Returns: | Formatted time difference
  Return type: | 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/<your_lang>/date_lang.php

`days_in_month`([$month = 0[, $year = '']])

  Parameters: |
  - $month (int) – a numeric month
  - $year (int) – a numeric year
  Returns: | Count of days in the specified month
  Return type: | 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.

`date_range`([$unix_start = ''[, $mixed = ''[, $is_unix = TRUE[, $format = 'Y-m-d']]]])

  Parameters: |
  - $unix_start (int) – UNIX timestamp of the range start date
  - $mixed (int) – UNIX timestamp of the range end date or interval in days
  - $is_unix (bool) – set to FALSE if $mixed is not a timestamp
  - $format (string) – Output date format, same as in `date()`
  Returns: | An array of dates
  Return type: | 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";
      }

`timezones`([$tz = ''])

  Parameters: |
  - $tz (string) – A numeric timezone
  Returns: | Hour difference from UTC
  Return type: | 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 `timezone_menu()`.

`timezone_menu`([$default = 'UTC'[, $class = ''[, $name = 'timezones'[, $attributes = '']]]])

  Parameters: |
  - $default (string) – Timezone
  - $class (string) – Class name
  - $name (string) – Menu name
  - $attributes (mixed) – HTML attributes
  Returns: | HTML drop down menu with time zones
  Return type: | string

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

  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/<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
--- | ---
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 - 07:00) 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