Timer Function in Form

Is it possible to add code in a form field on the edit page that would do the following:
onload:

1. Display and start counting the amout of time (hh:mm.ss format) since the page loaded
   after save:
   
2. save the value that is displayed when the end user hits the save button to the corresponding column in the database table
   Any ideas would be appreciated.
   Thanks,
   
   Jason