I usually check my email on the ipod while I'm still in bed, as part of the turning off the wake up alarm process. This morning, I checked it just before 6am, and found an email a student had sent at about 2am.
I think that's pretty much how student / faculty time works.
The only thing is, the student sent me an email before dawn on Monday, asking for a meeting early Monday, but not at one specific hour, and I'm guessing zie is not going to get back to me about which of the two time/places I can meet until after one of them has passed. I may be wrong; students often do with less sleep than I can, for sure.
But really, I don't feel too guilty since the student probably figured out the basics well before the predawn hours of Monday, and could have sent an email on Saturday sometime.