I apologize if this was already asked in this thread, but:
Is it in any way better to schedule the nap so that it's in the middle of the overall waking time or it doesn't matter at all?
Would this perhaps help in reducing the sleeping time?
Here's a 24 hour clock, to see this illustrated:

For example, if sleeping from midnight to 6 in the morning, the mid time between the waking hours would be 15:00 (so following this, you'd go to sleep at 14:30 for an hour).
But so far I've seen people (the OP and Steve) having the nap later, at 18:00 or so, even tho they wake up at 5 in the morning.