UNIX time?

[Sebastian]

Hi.

I am making a news system and integrating it into vb. Now, when someone makes a comment the date is stamped in UNIX time format, how do i determine if it was posted say 12 or 24 hours ago?

this is what i am trying to do.. get the unix time stamp from database with $row[3]

   $hrs_before_old = 24; 
   $today = mktime();
   if($row[3] + $hrs_before_old * 60 * 60 > $today) 
	   {
	   $posted = "<br>New!"; 
	   } else { 
	   $posted = ""; 
	   }

but it doesn't work, I want it to say "New" if it was posted within 24 hours, any help?