Time for sleeping

Napoleon slept 4 hours a day.

I heard of Don King who also sleep little.

So, now I have enough time to sleep ,it's needn't hurry in the morning and I get a sleep at 5 am. And if I didn't set alarm, I can sleep for 12 hours (but there may be headaches after all). Though if I go to bed at any time, it's hard to wake me up.

What should I do? Sleep 4 hours in every 8 hours?