The PHP version implements a friendly time display method (for example: 2 hours ago)

Complete php class, usually I use it with smary for quick use (plugins/function.rdate.php)

/*
 * Data time functions.
  // * 模块
 */
defined('TSKY') || die('Permission Denied!');

function fmtMonth($month){
	return date('F, Y',day2time($month.'01'));
}

//
function fmt_month($ts) {
	return strftime("%b,%Y",$ts);
}

// 03:02
function shartTime($ts) {
	return strftime("%H:%M",$ts);
}
// 03:02:01
function longTime($ts) {
	return strftime("%T",$ts);
}
//4月18日
function shortDate($ts) {
	return date("n月d日",$ts);
}
//2006年4月18日
function longDate($ts) {
	return date("Y年n月d日",$ts);
}

function dateTime($ts) {
	return date("Y年n月d日 H:i:s",$ts);
}
function fullDateTime($ts) {
	return date("Y年n月d日 ",$ts).week($ts);
}
function week($ts) {
	global $lang;
	return  $lang['weekDay'][date('w',$ts)];
}

function relatively_date($date) {
	if (!preg_match('/^d+$/', $date)) $date = strtotime(trim($date));
	$sec = time() - $date;
	switch(true){
		case $sec < 3600:
			return round($sec/60). ' 分钟前';
		case $sec < 86400:
			return round($sec/3600). ' 小时前';
		case $sec < (86400 * 7):
			return round($sec/86400). ' 天前';//days ago
		case $sec < (86400 * 7 * 4):
			return round($sec/(86400*7)). ' 周前'; //weeks ago
		default:
			return longDate($date);
	}
}

function nextMonth($month/*200512->200601*/){
	return date('Ym',strtotime('+1 month',strtotime($month.'01')));
}
function prevMonth($month/*200512->200511*/){
	return date('Ym',strtotime('-1 month',strtotime($month.'01')));
}
function prevDay($day/*20050826*/){
	$day = substr($day,0,8);
	return date('Ymd',strtotime('-1 day',strtotime($day)));
}

function nextDay($day/*20050826*/){
	$day = substr($day,0,8);
	return date('Ymd',strtotime('+1 day',strtotime($day)));
}
function nextExistsDay($day/*20050109*/){
	$day = nextDay($day);
	while(!hasTopic($day) && $day < TODAY){
		$day = nextDay($day);
	}
	return hasTopic($day) ? $day : false;
}
function prevExistsDay($day/*20050109*/){
	global $cfg;
	$day = prevDay($day);
	while(!hasTopic($day) && (int)$day > $cfg->origDate){
		$day = prevDay($day);
	}
	return hasTopic($day) ? $day : false;
}


function prev_day($day){$day = substr($day,0,8);return date('Ymd',strtotime('-1 day',strtotime($day)));}
function long_date($ts){return date("Y年n月d日",$ts);}
function day2time($day){return @strtotime($day);}





/*
echo "";
echo strftime("a%an");	//  a  星期二
echo strftime("A%An");	//  A  星期二
echo strftime("b%bn");	//  b  四月
echo strftime("B%Bn");	//  B  四月
echo strftime("c%cn");	//  c  2006-4-18 3:48:11
echo strftime("C%Cn");	//  C
echo strftime("d%dn");	//  d  18
echo strftime("D%Dn");	//  D
echo strftime("e%en");	//  e
echo strftime("g%gn");	//  g
echo strftime("G%Gn");	//  G
echo strftime("h%hn");	//  h
echo strftime("H%Hn");	//  H  03
echo strftime("I%In");	//  I  03
echo strftime("j%jn");	//  j  108
echo strftime("m%mn");	//  m  04
echo strftime("M%Mn");	//  M  48
echo strftime("n%nn");	//  n
echo strftime("p%pn");	//  p  上午
echo strftime("r%rn");	//  r
echo strftime("R%Rn");	//  R
echo strftime("S%Sn");	//  S  11
echo strftime("t%tn");	//  t
echo strftime("T%Tn");	//  T
echo strftime("u%un");	//  u
echo strftime("U%Un");	//  U  16
echo strftime("V%Vn");	//  V
echo strftime("W%Wn");	//  W  16
echo strftime("w%wn");	//  w  2
echo strftime("x%xn");	//  x  2006-4-18
echo strftime("X%Xn");	//  X  3:48:11
echo strftime("y%yn");	//  y  06
echo strftime("Y%Yn");	//  Y  2006
echo strftime("Z%Zn");	//  Z  中国标准时间
echo strftime("%%%n");	//  %
*/

function smarty_function_rdate($params, &$smarty){
	if (!isset($params['T'])){
		$smarty->trigger_error("rdate: missing 'T' parameter");
		return;
	}
	$date = $params['T'];
	if (!preg_match('/^d+$/', $date)) $date = strtotime(trim($date));
	$sec = time() - $date;
	switch(true){
		case $sec < 3600:
			return round($sec/60). ' 分钟前';
		case $sec < 86400:
			return round($sec/3600). ' 小时前';
		case $sec < (86400 * 7):
			return round($sec/86400). ' 天前';//days ago
		case $sec < (86400 * 7 * 4):
			return round($sec/(86400*7)). ' 周前'; //weeks ago
		default:
			return date("Y年n月d日",$date);
	}
}
?>