If you searched on google you would find 1000's of solutions. this is copied from PHP site
<?php
$td = time_diff($timestamp1-$timestamp2); // has to be a positive result
$td .= ($td=="now")? "":" ago"; // in this example "ago"
echo $td;
function time_diff($s){
$time = get\_post\_time('G', true, $post);
$s = time() - $time;
if($s>=1) {
$td = "$s sec";
}
if($s>59) {
$m = (int)($s/60);
$s = $s-($m\*60); // sec left over
$td = "$m min"; if($s>1) $td .="s";
}
if($m>59){
$hr = (int)($m/60);
$m = $m-($hr\*60); // min left over
$td = "$hr hr"; if($hr>1) $td .= "s";
if($m>0) $td .= ", $m min";
}
if($hr>23){
$d = (int)($hr/24);
$hr = $hr-($d\*24); // hr left over
$td = "$d day"; if($d>1) $td .= "s";
if($d<3){
if($hr>0) $td .= ", $hr hr"; if($hr>1) $td .= "s";
}
}
return $td;
}
?>
I wish I could believe there is an after life.