title: how to convert seconds into hhmmss
body: <p>i have looked everywhere to convert seconds into hh:mm:ss but couldn't find the right one</p>
  
  <p>i created a program that allows a user to enter two different times and then calculate the difference</p>
  
  <p>the times entered are split in hh * 3600 - mm * 60 - ss then converted into seconds and subtracted from each other to calculate difference in seconds</p>
  
  <p>for example 12:12:12 and 13:13:13 would give me 3661 seconds but i don't know how to convert the difference back into hh:mm:ss</p>
  
  <p>any help would be appreciated </p>