This can be used for comments and other from of communication to tell the time ago instead of the exact time which might not be correct to some one in another time zone.

The function only uses unix time stamp like the result of time();

Technique #1

<?php
function ago($time)
{
   $periods = array("second", "minute", "hour", "day", "week", "month", "year", "decade");
   $lengths = array("60","60","24","7","4.35","12","10");

   $now = time();

       $difference     = $now - $time;
       $tense         = "ago";

   for($j = 0; $difference >= $lengths[$j] && $j < count($lengths)-1; $j++) {
       $difference /= $lengths[$j];
   }

   $difference = round($difference);

   if($difference != 1) {
       $periods[$j].= "s";
   }

   return "$difference $periods[$j] 'ago' ";
}
?>

Technique #2

function _ago($tm,$rcs = 0) {
   $cur_tm = time(); $dif = $cur_tm-$tm;
   $pds = array('second','minute','hour','day','week','month','year','decade');
   $lngh = array(1,60,3600,86400,604800,2630880,31570560,315705600);
   for($v = sizeof($lngh)-1; ($v >= 0)&&(($no = $dif/$lngh[$v])<=1); $v--); if($v < 0) $v = 0; $_tm = $cur_tm-($dif%$lngh[$v]);

   $no = floor($no); if($no <> 1) $pds[$v] .='s'; $x=sprintf("%d %s ",$no,$pds[$v]);
   if(($rcs == 1)&&($v >= 1)&&(($cur_tm-$_tm) > 0)) $x .= time_ago($_tm);
   return $x;
}

Needs a time() value, and it will tell you how many seconds/minutes/hours/days/years/decades ago.

PHP Custom Time Ago Function

This PHP code reads the value of the date field on form post. This value will be passed as an argument to the custom timeago() function.

In timeago() function the given date is converted into timestamp using PHP built-in strtotime(). And, this timestamp is subtracted from the current timestamp to calculate elapsed time.

The time elapsed from the given date till now is used to calculate the time ago string. The code is,

<?php
	$strTimeAgo = ""; 
	if(!empty($_POST["date-field"])) {
		$strTimeAgo = timeago($_POST["date-field"]);
	}
	function timeago($date) {
	   $timestamp = strtotime($date);	
	   
	   $strTime = array("second", "minute", "hour", "day", "month", "year");
	   $length = array("60","60","24","30","12","10");

	   $currentTime = time();
	   if($currentTime >= $timestamp) {
			$diff     = time()- $timestamp;
			for($i = 0; $diff >= $length[$i] && $i < count($length)-1; $i++) {
			$diff = $diff / $length[$i];
			}

			$diff = round($diff);
			return $diff . " " . $strTime[$i] . "(s) ago ";
	   }
	}
	
?>