I start at 9am, but aim to be in work for 8am. I leave between 6:30 and 6:50am, which allows me sufficient time to cover the 20 mile commute (takes between 57 mins and 1hr 6min depending on the wind). Aiming to get in to work this early also gives me the option to extend the route by a few miles if the mood takes me. It also give me plenty of time to get cleaned up and changed, have some breakfast, read the news and fettle the bike if it needs it.
Takes a little longer in the winter on the hybrid with Marathon Winters, but still leave at same time, just take the direct route.