I usually sleep for 7-9 hours a day. Recently changed it from a day sleeping schedule (05:00 A. M. To 13.00 P. M.) to night one (24:00 midnight to 09:00 A. M.)

Yesterday was Friday, Indian standard time, and I went to sleep late around 04:00 A. M. And woke up at 06:00 A. M.

I just got through whole day of reading and writing, yet still feel fresh. How is this possible? Especially when I struggle to wake up on other days.

Plus, I feel more productive than ever. What explanation can there be for this sort of sleep occurrence?

Browse other questions tagged or ask your own question.