Quote (Serria @ Feb 12 2015 05:46pm)
Literally as much as you need. But to be more scientific falling and rising with sun is probably the most sufficient way unless it varies a lot. Even then you can vary with it to an extend.
Of course it will adapt it's not like it has anything to say to our mindless sleep deficit trend.
Falling and rising with the sun... Wtf?? During winter the sun could set ~5-6pm depending on location and time zones, and rise at 7-8 am etc.