In about 2 weeks I will try a new (for me) sleeping schedule. I'll sleep 90 minutes
4 times per 24 hours. It's some kind of a hybrid between biphasic and polyphasic . It doesn't save a lot of time, but you always awake with a clear mind. I tried polyphasic (6x30min), but failed after 4 days

. Usually, I sleep a lot (9-12 hours), so this will anyway be better for me if it works. What do you think?