A: It's time to get up.
B: What time is it?
A: lt，s seven o'clock.
A: I stayed up late last night. I'm sleepy now.
B: What did you do last night?
A: I'd been busy writing a paper.
表示到做什么事情的时间了，可以用Its time to ...或者It's time for ...如：It's time to have supper.或者 也可以说 It's time for supper.
stay up late 是“睡得很晚”的意思，如果说没睡，则是 stay awake。如：I stayed awake the wholenight. 昨晚我整夜没睡。