I usually go to sleep sometime between midnight and 1am. My alarm is set for 7:30am and sometimes I'll hit the snooze button a couple of times but I'm usually out of bed about 8 and go to work at 10:00. I usually leave the drapes/shade open on my south and east bedroom windows, and the sun helps wake me up.
I call it a sleep in anytime that I turn off the alarm clock the night before and pull down the window shades. Sometimes I'm up at about the regular time, other times not. I hardly ever seem to sleep past about ten though. I may just lie there dozing in and out, not really asleep, but not awake either. Sometimes I'll grab the newspaper and read part of it in bed, then fall back asleep.
What makes it a sleep in isn't what the clock says, it's that I don't have to get up until I want to.
If I'm really tired or stressed, I'm more likely to go to bed early than to sleep late.
Lindy