4 files changed, 302 insertions, 74 deletions
diff --git a/phpBB/includes/datetime.php b/phpBB/includes/datetime.php
new file mode 100644
index 0000000000..15e3c8b0b7
--- /dev/null
+++ b/phpBB/includes/datetime.php
@@ -0,0 +1,173 @@
+<?php
+/**
+*
+* @package phpBB3
+* @version $Id$
+* @copyright (c) 2010 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+*/
+
+/**
+* phpBB custom extensions to the PHP DateTime class
+* This handles the relative formats phpBB employs
+*/
+class phpbb_datetime extends DateTime
+{
+	/**
+	* String used to wrap the date segment which should be replaced by today/tomorrow/yesterday
+	*/
+	const RELATIVE_WRAPPER = '|';
+
+	/**
+	* @var user User who is the context for this DateTime instance
+	*/
+	protected $_user;
+
+	/**
+	* @var array Date formats are preprocessed by phpBB, to save constant recalculation they are cached.
+	*/
+	static protected $format_cache = array();
+
+	/**
+	* Constructs a new instance of phpbb_datetime, expanded to include an argument to inject
+	* the user context and modify the timezone to the users selected timezone if one is not set.
+	*
+	* @param string $time String in a format accepted by strtotime().
+	* @param DateTimeZone $timezone Time zone of the time.
+	* @param user User object for context.
+	*/
+	public function __construct($time = 'now', DateTimeZone $timezone = null, $user = null)
+	{
+		$this->_user	= $user ? $user : $GLOBALS['user'];
+
+		$timezone		= (!$timezone && $this->_user->tz instanceof DateTimeZone) ? $this->_user->tz : $timezone;
+
+		parent::__construct($time, $timezone);
+	}
+
+	/**
+	* Returns a UNIX timestamp representation of the date time.
+	*
+	* @internal This method is for backwards compatibility with 5.2, hence why it doesn't use our method naming standards.
+	* @return int UNIX timestamp
+	*/
+	public function getTimestamp()
+	{
+		static $compat;
+
+		if (!isset($compat))
+		{
+			$compat = !method_exists('DateTime', 'getTimestamp');
+		}
+
+		return !$compat ? parent::getTimestamp() : (int) parent::format('U');
+	}
+
+	/**
+	* Formats the current date time into the specified format
+	*
+	* @param string $format Optional format to use for output, defaults to users chosen format
+	* @param boolean $force_absolute Force output of a non relative date
+	* @return string Formatted date time
+	*/
+	public function format($format = '', $force_absolute = false)
+	{
+		$format		= $format ? $format : $this->_user->date_format;
+		$format		= self::_format_cache($format, $this->_user);
+		$relative	= ($format['is_short'] && !$force_absolute);
+		$now		= new self('now', $this->_user->tz, $this->_user);
+
+		$timestamp	= $this->getTimestamp();
+		$now_ts		= $now->getTimeStamp();
+
+		$delta		= $now_ts - $timestamp;
+
+		if ($relative)
+		{
+			// Check the delta is less than or equal to 1 hour
+			// and the delta not more than a minute in the past
+			// and the delta is either greater than -5 seconds or timestamp and current time are of the same minute (they must be in the same hour already)
+			// finally check that relative dates are supported by the language pack
+			if ($delta <= 3600 && $delta > -60 && ($delta >= -5 || (($now_ts / 60) % 60) == (($timestamp / 60) % 60)) && isset($this->_user->lang['datetime']['AGO']))
+			{
+				return $this->_user->lang(array('datetime', 'AGO'), max(0, (int) floor($delta / 60)));
+			}
+			else
+			{
+				$midnight = clone $now;
+				$midnight->setTime(0, 0, 0);
+
+				$midnight	= $midnight->getTimestamp();
+
+				$day = false;
+
+				if ($timestamp > $midnight + 86400)
+				{
+					$day = 'TOMORROW';
+				}
+				else if ($timestamp > $midnight)
+				{
+					$day = 'TODAY';
+				}
+				else if ($timestamp > $midnight - 86400)
+				{
+					$day = 'YESTERDAY';
+				}
+
+				if ($day !== false)
+				{
+					// Format using the short formatting and finally swap out the relative token placeholder with the correct value
+					return str_replace(self::RELATIVE_WRAPPER . self::RELATIVE_WRAPPER, $this->_user->lang['datetime'][$day], strtr(parent::format($format['format_short']), $format['lang']));
+				}
+			}
+		}
+
+		return strtr(parent::format($format['format_long']), $format['lang']);
+	}
+
+	/**
+	* Magic method to convert DateTime object to string
+	*
+	* @return Formatted date time, according to the users default settings.
+	*/
+	public function __toString()
+	{
+		return $this->format();
+	}
+
+	/**
+	* Pre-processes the specified date format
+	*
+	* @param string $format Output format
+	* @param user $user User object to use for localisation
+	* @return array Processed date format
+	*/
+	static protected function _format_cache($format, $user)
+	{
+		$lang = $user->lang_name;
+
+		if (!isset(self::$format_cache[$lang]))
+		{
+			self::$format_cache[$lang] = array();
+		}
+
+		if (!isset(self::$format_cache[$lang][$format]))
+		{
+			// Is the user requesting a friendly date format (i.e. 'Today 12:42')?
+			self::$format_cache[$lang][$format] = array(
+				'is_short'		=> strpos($format, self::RELATIVE_WRAPPER) !== false,
+				'format_short'	=> substr($format, 0, strpos($format, self::RELATIVE_WRAPPER)) . self::RELATIVE_WRAPPER . self::RELATIVE_WRAPPER . substr(strrchr($format, self::RELATIVE_WRAPPER), 1),
+				'format_long'	=> str_replace(self::RELATIVE_WRAPPER, '', $format),
+				'lang'			=> $user->lang['datetime'],
+			);
+
+			// Short representation of month in format? Some languages use different terms for the long and short format of May
+			if ((strpos($format, '\M') === false && strpos($format, 'M') !== false) || (strpos($format, '\r') === false && strpos($format, 'r') !== false))
+			{
+				self::$format_cache[$lang][$format]['lang']['May'] = $user->lang['datetime']['May_short'];
+			}
+		}
+
+		return self::$format_cache[$lang][$format];
+	}
+}
diff --git a/phpBB/includes/functions.php b/phpBB/includes/functions.php
index 95f2cf8d26..3ec4b76091 100644
--- a/phpBB/includes/functions.php
+++ b/phpBB/includes/functions.php
@@ -1068,30 +1068,116 @@ function style_select($default = '', $all = false)
 	return $style_options;
 }
 
+function phpbb_format_timezone_offset($tz_offset)
+{
+	$sign = ($tz_offset < 0) ? '-' : '+';
+	$time_offset = abs($tz_offset);
+
+	$offset_seconds	= $time_offset % 3600;
+	$offset_minutes	= $offset_seconds / 60;
+	$offset_hours	= ($time_offset - $offset_seconds) / 3600;
+
+	$offset_string	= sprintf("%s%02d:%02d", $sign, $offset_hours, $offset_minutes);
+	return $offset_string;
+}
+
+// Compares two time zone labels.
+// Arranges them in increasing order by timezone offset.
+// Places UTC before other timezones in the same offset.
+function tz_select_compare($a, $b)
+{
+	$a_sign = $a[3];
+	$b_sign = $b[3];
+	if ($a_sign != $b_sign)
+	{
+		return $a_sign == '-' ? -1 : 1;
+	}
+
+	$a_offset = substr($a, 4, 5);
+	$b_offset = substr($b, 4, 5);
+	if ($a_offset == $b_offset)
+	{
+		$a_name = substr($a, 12);
+		$b_name = substr($b, 12);
+		if ($a_name == $b_name)
+		{
+			return 0;
+		} else if ($a_name == 'UTC')
+		{
+			return -1;
+		} else if ($b_name == 'UTC')
+		{
+			return 1;
+		}
+		else
+		{
+			return $a_name < $b_name ? -1 : 1;
+		}
+	}
+	else
+	{
+		if ($a_sign == '-')
+		{
+			return $a_offset > $b_offset ? -1 : 1;
+		}
+		else
+		{
+			return $a_offset < $b_offset ? -1 : 1;
+		}
+	}
+}
+
 /**
 * Pick a timezone
+* @todo Possible HTML escaping
 */
 function tz_select($default = '', $truncate = false)
 {
 	global $user;
 
+	static $timezones;
+
+	if (!isset($timezones))
+	{
+		$timezones = DateTimeZone::listIdentifiers();
+
+		foreach ($timezones as &$timezone)
+		{
+			$tz = new DateTimeZone($timezone);
+			$dt = new phpbb_datetime('now', $tz);
+			$offset = $dt->getOffset();
+			$offset_string = phpbb_format_timezone_offset($offset);
+			$timezone = 'GMT' . $offset_string . ' - ' . $timezone;
+		}
+		unset($timezone);
+
+		usort($timezones, 'tz_select_compare');
+	}
+
 	$tz_select = '';
-	foreach ($user->lang['tz_zones'] as $offset => $zone)
+
+	foreach ($timezones as $timezone)
 	{
-		if ($truncate)
+		if (isset($user->lang['timezones'][$timezone]))
 		{
-			$zone_trunc = truncate_string($zone, 50, 255, false, '...');
+			$title = $label = $user->lang['timezones'][$timezone];
 		}
 		else
 		{
-			$zone_trunc = $zone;
+			// No label, we'll figure one out
+			// @todo rtl languages?
+			$bits = explode('/', str_replace('_', ' ', $timezone));
+
+			$title = $label = implode(' - ', $bits);
 		}
 
-		if (is_numeric($offset))
+		if ($truncate)
 		{
-			$selected = ($offset == $default) ? ' selected="selected"' : '';
-			$tz_select .= '<option title="' . $zone . '" value="' . $offset . '"' . $selected . '>' . $zone_trunc . '</option>';
+			$label = truncate_string($label, 50, 255, false, '...');
 		}
+
+		$selected = ($timezone === $default) ? ' selected="selected"' : '';
+		$tz_select .= '<option title="' . $title . '" value="' . $timezone . '"' . $selected . '>' . $label . '</option>';
 	}
 
 	return $tz_select;
diff --git a/phpBB/includes/functions_profile_fields.php b/phpBB/includes/functions_profile_fields.php
index 3399334f94..1c15ef897f 100644
--- a/phpBB/includes/functions_profile_fields.php
+++ b/phpBB/includes/functions_profile_fields.php
@@ -554,9 +554,12 @@ class custom_profile
 				else if ($day && $month && $year)
 				{
 					global $user;
-					// Date should display as the same date for every user regardless of timezone, so remove offset
-					// to compensate for the offset added by phpbb_user::format_date()
-					return $user->format_date(gmmktime(0, 0, 0, $month, $day, $year) - ($user->timezone + $user->dst), $user->lang['DATE_FORMAT'], true);
+					// Date should display as the same date for every user regardless of timezone
+
+					return $user->create_datetime()
+						->setDate($year, $month, $day)
+						->setTime(0, 0, 0)
+						->format($user->lang['DATE_FORMAT'], true);
 				}
 
 				return $value;
diff --git a/phpBB/includes/user.php b/phpBB/includes/user.php
index ce9c804f23..4c62dd93d7 100644
--- a/phpBB/includes/user.php
+++ b/phpBB/includes/user.php
@@ -29,8 +29,7 @@ class phpbb_user extends phpbb_session
 	var $help = array();
 	var $theme = array();
 	var $date_format;
-	var $timezone;
-	var $dst;
+	public $tz;
 
 	var $lang_name = false;
 	var $lang_id = false;
@@ -79,15 +78,13 @@ class phpbb_user extends phpbb_session
 			$this->lang_name = (file_exists($this->lang_path . $this->data['user_lang'] . "/common.$phpEx")) ? $this->data['user_lang'] : basename($config['default_lang']);
 
 			$this->date_format = $this->data['user_dateformat'];
-			$this->timezone = $this->data['user_timezone'] * 3600;
-			$this->dst = $this->data['user_dst'] * 3600;
+			$this->tz = $this->data['user_timezone'];
 		}
 		else
 		{
 			$this->lang_name = basename($config['default_lang']);
 			$this->date_format = $config['default_dateformat'];
-			$this->timezone = $config['board_timezone'] * 3600;
-			$this->dst = $config['board_dst'] * 3600;
+			$this->tz = $config['board_timezone'];
 
 			/**
 			* If a guest user is surfing, we try to guess his/her language first by obtaining the browser language
@@ -126,6 +123,14 @@ class phpbb_user extends phpbb_session
 			*/
 		}
 
+		if (is_numeric($this->tz))
+		{
+			// Might still be numeric by chance
+			$this->tz = sprintf('Etc/GMT%+d', ($this->tz + ($this->data['user_id'] != ANONYMOUS ? $this->data['user_dst'] : $config['board_dst'])));
+		}
+
+		$this->tz = new DateTimeZone($this->tz);
+
 		// We include common language file here to not load it every time a custom language file is included
 		$lang = &$this->lang;
 
@@ -615,70 +620,31 @@ class phpbb_user extends phpbb_session
 	*/
 	function format_date($gmepoch, $format = false, $forcedate = false)
 	{
-		static $midnight;
-		static $date_cache;
-
-		$format = (!$format) ? $this->date_format : $format;
-		$now = time();
-		$delta = $now - $gmepoch;
-
-		if (!isset($date_cache[$format]))
-		{
-			// Is the user requesting a friendly date format (i.e. 'Today 12:42')?
-			$date_cache[$format] = array(
-				'is_short'      => strpos($format, '|'),
-				'format_short'  => substr($format, 0, strpos($format, '|')) . '||' . substr(strrchr($format, '|'), 1),
-				'format_long'   => str_replace('|', '', $format),
-				'lang'          => $this->lang['datetime'],
-			);
-
-			// Short representation of month in format? Some languages use different terms for the long and short format of May
-			if ((strpos($format, '\M') === false && strpos($format, 'M') !== false) || (strpos($format, '\r') === false && strpos($format, 'r') !== false))
-			{
-				$date_cache[$format]['lang']['May'] = $this->lang['datetime']['May_short'];
-			}
-		}
-
-		// Zone offset
-		$zone_offset = $this->timezone + $this->dst;
+		static $utc;
 
-		// Show date < 1 hour ago as 'xx min ago' but not greater than 60 seconds in the future
-		// A small tolerence is given for times in the future but in the same minute are displayed as '< than a minute ago'
-		if ($delta < 3600 && $delta > -60 && ($delta >= -5 || (($now / 60) % 60) == (($gmepoch / 60) % 60)) && $date_cache[$format]['is_short'] !== false && !$forcedate && isset($this->lang['datetime']['AGO']))
+		if (!isset($utc))
 		{
-			return $this->lang(array('datetime', 'AGO'), max(0, (int) floor($delta / 60)));
+			$utc = new DateTimeZone('UTC');
 		}
 
-		if (!$midnight)
-		{
-			list($d, $m, $y) = explode(' ', gmdate('j n Y', time() + $zone_offset));
-			$midnight = gmmktime(0, 0, 0, $m, $d, $y) - $zone_offset;
-		}
-
-		if ($date_cache[$format]['is_short'] !== false && !$forcedate && !($gmepoch < $midnight - 86400 || $gmepoch > $midnight + 172800))
-		{
-			$day = false;
+		$time = new phpbb_datetime("@$gmepoch", $utc, $this);
+		$time->setTimezone($this->tz);
 
-			if ($gmepoch > $midnight + 86400)
-			{
-				$day = 'TOMORROW';
-			}
-			else if ($gmepoch > $midnight)
-			{
-				$day = 'TODAY';
-			}
-			else if ($gmepoch > $midnight - 86400)
-			{
-				$day = 'YESTERDAY';
-			}
-
-			if ($day !== false)
-			{
-				return str_replace('||', $this->lang['datetime'][$day], strtr(@gmdate($date_cache[$format]['format_short'], $gmepoch + $zone_offset), $date_cache[$format]['lang']));
-			}
-		}
+		return $time->format($format, $forcedate);
+	}
 
-		return strtr(@gmdate($date_cache[$format]['format_long'], $gmepoch + $zone_offset), $date_cache[$format]['lang']);
+	/**
+	* Create a phpbb_datetime object in the context of the current user
+	*
+	* @since 3.1
+	* @param string $time String in a format accepted by strtotime().
+	* @param DateTimeZone $timezone Time zone of the time.
+	* @return phpbb_datetime Date time object linked to the current users locale
+	*/
+	public function create_datetime($time = 'now', DateTimeZone $timezone = null)
+	{
+		$timezone = $timezone ?: $this->tz;
+		return new phpbb_datetime($time, $timezone, $this);
 	}
 
 	/**