Repeat a task with time delay in winjs

Repeat a task with time delay in winjs

I am developing an app in winjs, and I need to periodically do some task
with a constant and specified delay between each pair of executions.
In particular, I am intending to update the user's position on the map
every 30 seconds.
I am not quite sure how to implement the task scheduler in winjs. I have
looked at the background task class, but that doesnt seem to be much
helpful in my case.
Any help would be helpful here.