I have, at one time or another, both stayed up until and gotten up at every small hour of the morning.
The former of the two – the staying up late – seems to happen, or has happened, mostly in relation to a deadline of some sort, be it one of school or a self-imposed project with a time constraint (e.g. a homemade birthday gift for an out-of-town friend).
(I also recall, during university, having stayed up and out way late at some club, party, or other manner of social gathering, but those days, alas, are largely over now.)
Like many writers, I am balancing my as-yet unpaid writing efforts with my paid day job.
At certain times of the year, my job requires me to work overtime. One such occasion recently occurred, and at the end of my protracted work day, I found myself riding the elevator down with my boss, who is also an up-and-coming writer.
We got to chatting about how we would spend the rest of our respective evenings, or what remained of them. This morphed into talk of how we usually spend our evenings, in particular as related to our writing.