I think I found it, but more importantly, I found this: "LOL that's only day crew...they don't matter "
The timer does begin as soon as it's accepted. If you're familiar with using scripts you can install Turkmaster, with it you can set up your pandas and have them alert you with a noise and/or notification when you've caught one. Otherwise you could just refresh the hits assigned to you page once in a while to see if you got any. That page will also show how many hits you have in your queue.
The time begins as soon as you accept any hit, so it's not a good idea to panda real short timers unless you are doin them as your are catching them, say like a Mylikes which has a min thirty on one of their hits