This will take the date and time posted of an object in mySQL and convert it to a human readable form through PHP. It has 3 different modes of displaying the age:

• The number of hours and minutes if the object was posted within the day.
• The number of days if the object was posted within a month.
• The date if the object was posted over a month ago.

It uses the mySQL timediff() function to determine the number of hours since the object was added. This requires either a datetime field or concatenated date and time fields. You need to pass the PHP function this value to get a human readable form. For example:

select timediff(concat(curdate(), ' ', curtime()), concat(date, ' ',time)) as hours ... 

The results will look like this:

a few seconds ago
1 min ago
5 mins ago
2 hours 3 mins ago
3 days ago
Jan 20, 2012

function get_age($hours)
{
    list($hour, $min, $sec) = split(":", $hours);
    if($hour > 24) $days = round($hour / 24);
    else $days = 0;

    if($days >= 61) {
        $date = date('M d, Y', strtotime("-$hour hours"));
        return $date;
    }
    else if($days >= 1) {
        $age = "$days day";
        if($days > 1) { $age .= "s"; }
    }
    else {
        if($hour > 0) {
            $hour = ltrim($hour, '0');
            $age .= " $hour hour";
            if($hour > 1) { $age .= "s"; }
        }
        if($min > 0) {
            $min = ltrim($min, '0'); 
            if(!$min) $min = '0';
            $age .= " $min min";
            if($min != 1) { $age .= "s"; }
        }
    }

    if($min < 1 and $hour < 1) { $age = 'a few seconds'; }
    $age .= ' ago';

    return $age;
}