date.php

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<?php
/**
* @version		$Id: date.php 10827 2008-08-27 23:10:15Z charlvn $
* @package		Joomla.Framework
* @subpackage	Utilities
* @copyright	Copyright (C) 2005 - 2008 Open Source Matters. All rights reserved.
* @license		GNU/GPL, see LICENSE.php
* Joomla! is free software. This version may have been modified pursuant
* to the GNU General Public License, and as distributed it includes or
* is derivative of works licensed under the GNU General Public License or
* other free or open source software licenses.
* See COPYRIGHT.php for copyright notices and details.
*/

// Check to ensure this file is within the rest of the framework
defined('JPATH_BASE') or die();

/**
 * JDate is a class that stores a date
 *
 * @package		Joomla.Framework
 * @subpackage	Utilities
 * @since		1.5
 */
class JDate extends JObject
{
	/**
	 * Unix timestamp
	 *
	 * @var     int|boolean
	 * @access  protected
	 */
	var $_date = false;

	/**
	 * Time offset (in seconds)
	 *
	 * @var     string
	 * @access  protected
	 */
	var $_offset = 0;

	/**
	 * Creates a new instance of JDate representing a given date.
	 *
	 * Accepts RFC 822, ISO 8601 date formats as well as unix time stamps.
	 * If not specified, the current date and time is used.
	 *
	 * @param mixed $date optional the date this JDate will represent.
	 * @param int $tzOffset optional the timezone $date is from
	 */
	function __construct($date = 'now', $tzOffset = 0)
	{
		if ($date == 'now' || empty($date))
		{
			$this->_date = strtotime(gmdate("M d Y H:i:s", time()));
			return;
		}

		$tzOffset *= 3600;
		if (is_numeric($date))
		{
			$this->_date = $date - $tzOffset;
			return;
		}

		if (preg_match('~(?:(?:Mon|Tue|Wed|Thu|Fri|Sat|Sun),\\s+)?(\\d{1,2})\\s+([a-zA-Z]{3})\\s+(\\d{4})\\s+(\\d{2}):(\\d{2}):(\\d{2})\\s+(.*)~i',$date,$matches))
		{
			$months = Array(
				'jan' => 1, 'feb' => 2, 'mar' => 3, 'apr' => 4,
				'may' => 5, 'jun' => 6, 'jul' => 7, 'aug' => 8,
				'sep' => 9, 'oct' => 10, 'nov' => 11, 'dec' => 12
			);
			$matches[2] = strtolower($matches[2]);
			if (! isset($months[$matches[2]])) {
				return;
			}
			$this->_date = mktime(
				$matches[4], $matches[5], $matches[6],
				$months[$matches[2]], $matches[1], $matches[3]
			);
			if ($this->_date === false) {
				return;
			}

			if ($matches[7][0] == '+') {
				$tzOffset = 3600 * substr($matches[7], 1, 2)
					+ 60 * substr($matches[7], -2);
			} elseif ($matches[7][0] == '-') {
				$tzOffset = -3600 * substr($matches[7], 1, 2)
					- 60 * substr($matches[7], -2);
			} else {
				if (strlen($matches[7]) == 1) {
					$oneHour = 3600;
					$ord = ord($matches[7]);
					if ($ord < ord('M')) {
						$tzOffset = (ord('A') - $ord - 1) * $oneHour;
					} elseif ($ord >= ord('M') && $matches[7] != 'Z') {
						$tzOffset = ($ord - ord('M')) * $oneHour;
					} elseif ($matches[7] == 'Z') {
						$tzOffset = 0;
					}
				}
				switch ($matches[7]) {
					case 'UT':
					case 'GMT': $tzOffset = 0;
				}
			}
			$this->_date -= $tzOffset;
			return;
		}
		if (preg_match('~(\\d{4})-(\\d{2})-(\\d{2})[T\s](\\d{2}):(\\d{2}):(\\d{2})(.*)~', $date, $matches))
		{
			$this->_date = mktime(
				$matches[4], $matches[5], $matches[6],
				$matches[2], $matches[3], $matches[1]
			);
			if ($this->_date == false) {
				return;
			}
			if (isset($matches[7][0])) {
				if ($matches[7][0] == '+' || $matches[7][0] == '-') {
					$tzOffset = 60 * (
						substr($matches[7], 0, 3) * 60 + substr($matches[7], -2)
					);
				} elseif ($matches[7] == 'Z') {
					$tzOffset = 0;
				}
			}
			$this->_date -= $tzOffset;
			return;
		}
        $this->_date = (strtotime($date) == -1) ? false : strtotime($date);
		if ($this->_date) {
			$this->_date -= $tzOffset;
		}
	}

	/**
	 * Set the date offset (in hours)
	 *
	 * @access public
	 * @param float The offset in hours
	 */
	function setOffset($offset) {
		$this->_offset = 3600 * $offset;
	}

	/**
	 * Get the date offset (in hours)
	 *
	 * @access public
	 * @return integer
	 */
	function getOffset() {
		return ((float) $this->_offset) / 3600.0;
	}

	/**
	 * Gets the date as an RFC 822 date.
	 *
	 * @return a date in RFC 822 format
	 * @link http://www.ietf.org/rfc/rfc2822.txt?number=2822 IETF RFC 2822
	 * (replaces RFC 822)
	 */
	function toRFC822($local = false)
	{
		$date = ($local) ? $this->_date + $this->_offset : $this->_date;
		$date = ($this->_date !== false) ? date('D, d M Y H:i:s', $date).' +0000' : null;
		return $date;
	}

	/**
	 * Gets the date as an ISO 8601 date.
	 *
	 * @return a date in ISO 8601 (RFC 3339) format
	 * @link http://www.ietf.org/rfc/rfc3339.txt?number=3339 IETF RFC 3339
	 */
	function toISO8601($local = false)
	{
		$date   = ($local) ? $this->_date + $this->_offset : $this->_date;
		$offset = $this->getOffset();
        $offset = ($local && $this->_offset) ? sprintf("%+03d:%02d", $offset, abs(($offset-intval($offset))*60) ) : 'Z';
        $date   = ($this->_date !== false) ? date('Y-m-d\TH:i:s', $date).$offset : null;
		return $date;
	}

	/**
	 * Gets the date as in MySQL datetime format
	 *
	 * @return a date in MySQL datetime format
	 * @link http://dev.mysql.com/doc/refman/4.1/en/datetime.html MySQL DATETIME
	 * format
	 */
	function toMySQL($local = false)
	{
		$date = ($local) ? $this->_date + $this->_offset : $this->_date;
		$date = ($this->_date !== false) ? date('Y-m-d H:i:s', $date) : null;
		return $date;
	}

	/**
	 * Gets the date as UNIX time stamp.
	 *
	 * @return a date as a unix time stamp
	 */
	function toUnix($local = false)
	{
		$date = null;
		if ($this->_date !== false) {
			$date = ($local) ? $this->_date + $this->_offset : $this->_date;
		}
		return $date;
	}

	/**
	 * Gets the date in a specific format
	 *
	 * Returns a string formatted according to the given format. Month and weekday names and
	 * other language dependent strings respect the current locale
	 *
	 * @param string $format  The date format specification string (see {@link PHP_MANUAL#strftime})
	 * @return a date in a specific format
	 */
	function toFormat($format = '%Y-%m-%d %H:%M:%S')
	{
		$date = ($this->_date !== false) ? $this->_strftime($format, $this->_date + $this->_offset) : null;

		return $date;
	}

	/**
	 * Translates needed strings in for JDate::toFormat (see {@link PHP_MANUAL#strftime})
	 *
	 * @access protected
	 * @param string $format The date format specification string (see {@link PHP_MANUAL#strftime})
	 * @param int $time Unix timestamp
	 * @return string a date in the specified format
	 */
	function _strftime($format, $time)
	{
		if(strpos($format, '%a') !== false)
			$format = str_replace('%a', $this->_dayToString(date('w', $time), true), $format);
		if(strpos($format, '%A') !== false)
			$format = str_replace('%A', $this->_dayToString(date('w', $time)), $format);
		if(strpos($format, '%b') !== false)
			$format = str_replace('%b', $this->_monthToString(date('n', $time), true), $format);
		if(strpos($format, '%B') !== false)
			$format = str_replace('%B', $this->_monthToString(date('n', $time)), $format);
		$date = strftime($format, $time);
		return $date;
	}

	/**
	 * Translates month number to string
	 *
	 * @access protected
	 * @param int $month The numeric month of the year
	 * @param bool $abbr Return the abreviated month string?
	 * @return string month string
	 */
	function _monthToString($month, $abbr = false)
	{
		switch ($month)
		{
			case 1:  return $abbr ? JText::_('JANUARY_SHORT')   : JText::_('JANUARY');
			case 2:  return $abbr ? JText::_('FEBRUARY_SHORT')  : JText::_('FEBRUARY');
			case 3:  return $abbr ? JText::_('MARCH_SHORT')     : JText::_('MARCH');
			case 4:  return $abbr ? JText::_('APRIL_SHORT')     : JText::_('APRIL');
			case 5:  return $abbr ? JText::_('MAY_SHORT')       : JText::_('MAY');
			case 6:  return $abbr ? JText::_('JUNE_SHORT')      : JText::_('JUNE');
			case 7:  return $abbr ? JText::_('JULY_SHORT')      : JText::_('JULY');
			case 8:  return $abbr ? JText::_('AUGUST_SHORT')    : JText::_('AUGUST');
			case 9:  return $abbr ? JText::_('SEPTEMBER_SHORT')  : JText::_('SEPTEMBER');
			case 10: return $abbr ? JText::_('OCTOBER_SHORT')   : JText::_('OCTOBER');
			case 11: return $abbr ? JText::_('NOVEMBER_SHORT')  : JText::_('NOVEMBER');
			case 12: return $abbr ? JText::_('DECEMBER_SHORT')  : JText::_('DECEMBER');
		}
	}

	/**
	 * Translates day of week number to string
	 *
	 * @access protected
	 * @param int $day The numeric day of the week
	 * @param bool $abbr Return the abreviated day string?
	 * @return string day string
	 */
	function _dayToString($day, $abbr = false)
	{
		switch ($day)
		{
			case 0: return $abbr ? JText::_('SUN') : JText::_('SUNDAY');
			case 1: return $abbr ? JText::_('MON') : JText::_('MONDAY');
			case 2: return $abbr ? JText::_('TUE') : JText::_('TUESDAY');
			case 3: return $abbr ? JText::_('WED') : JText::_('WEDNESDAY');
			case 4: return $abbr ? JText::_('THU') : JText::_('THURSDAY');
			case 5: return $abbr ? JText::_('FRI') : JText::_('FRIDAY');
			case 6: return $abbr ? JText::_('SAT') : JText::_('SATURDAY');
		}
	}

}