I'm planning on riding a 1000km Perm this year, with "day 1" being about 400km starting at 11pm. The idea is that I would get to a Travelodge in the evening of the following day in time for a shower, something to eat and a few hours sleep in a comfy bed.
"Day2" and "Day3" of the 1000 would then be 2 rides of about 300km starting at dawn with another Travelodge stop after Day2. That's the plan anyway and al least fits the control times, but whether it fits my abilities remains to be seen.
So a late evening start for a 400 might work out. If you are think you'll be riding throught the night, getting it done early in the ride while you are still fresh makes sense. This weekend's Plains 300 works very well that way, and I'll be on that unless the weather is unfriendly