Best time(s) to drive into the city from the east?

Starting a new job in the center and I'm wondering which hours to avoid and which I should try out?

If I arrive at 7.45 at the end of the motorway, I can be in the center by 8:20 which isn't too bad.

If I arrive later, it starts getting exponentially worse (including finding parking)

What if I drive in later, let's say around 9:30 or 10 or 10:30... how bad will the traffic be?