tracking effort - is there some stopwatch in the platform ?

Hi all,
   an employee will track the time spent in one activity and I need to handle this. See that it is different from the time elapsed on the task on his responsibility. I have created a stop watch in JS but it doesn´t work in IE (only Firefox) and I had problems to get this value inside Outsystems. Someone could give me a tip how to solve this ?
I attached the JS and part of screen to show what I am doing.

why do you need to solve this on the client side?

just have 2 buttons. 
1 start button, which will record a timestamp/ticks of starting the activity
2. end button, which will record a new timestamp/ticks of ending the activity.
in this way you keep it on the server and have no problem.

How can I keep it on server and show the elapsed time in the right way ?  If I do that I need to refresh the screen everytime. Am I right ?  Are you suggesting the user calculate the elapsed time by hand ?