Ton has it.
If I didn’t work full time, up at 5am, nap at 2pm and bed for 10/10.30pm would be ideal for my body clock.
Most of last year to try to offset too many hours behind a desk I would get up at 5am to fit in an hours walk before getting the kids ready for school from 6.15 am. Just due to life commitments I would struggle to get in bed before 10pm at all and with that routine and mild daily exercise I felt relaxed, had energy, good levels of concentration and rarely felt tired. An afternoon nap in an armchair for 30 minutes really would have been the icing on the cake.
Now days getting up at 6am, without the daily walk, sitting behind the desk and bed for 10.30/11pm I generally feel like rubbish. I need to get back into last years routine.