need help with simple timing code

Hi guys! This is the code that i have on the timer script. It works up to the minutes, but I am trying to figure out how to add hours and days to it. I really need help with this. can anyone figure this out?
here is the code:

function Timing()
 {
     if (timer > 0) {
    	 
      	 hourdisplay = parseInt( (timer / 60)/ 60 ).ToString();
     
         
         minsDisplay = parseInt( timer / 60 ).ToString();
         
        
         secsDisplay = parseInt( timer ).ToString();
          
         if ( (timer - ( parseInt(minsDisplay) * 60)) > 10 ) {
              secsDisplay = parseInt( timer - ( parseInt(minsDisplay) * 60) ).ToString();
         } 
         else {
             secsDisplay = "0" + parseInt( timer - ( parseInt(minsDisplay) * 60) ).ToString();
         }
         
        
     } 
     else {
          timer += timer;
     }
     displayText.text = minsDisplay + " : " + secsDisplay;
 }

If you want to display seconds, minutes, hours, and days separately (in their own variable) use something like this:

daysdisplay = parseInt( timer / 60 / 60 / 24 ).ToString();
hourdisplay = parseInt( timer / 60 / 60 % 24 ).ToString();
minsDisplay = parseInt( timer / 60 % 60 ).ToString();
secsDisplay = parseInt( timer % 60).ToString();

Hope that helps!