Because I can't remember who I was talking with. (You'd be surprised how often that happens.)
So here's a freebie for anyone who wants it.
Our boys all share a room. Always have. Some of them wake earlier than others. Not a problem, now that they can all tell time. But when they were smaller I did not appreciate little people getting out of bed at oh-dark-thirty and possibly disturbing their sleeping brothers at oh-dark-thirty to come wake me up at oh-dark-thirty to ask if it was time to get up. Because, as previously noted, I am not very godly at that hour.
It also doesn't help that we live at a latitude where it can be dark until 8AM in the winter, yet light by 4:30AM in the summer. Light is not a reliable indicator.
I took a cheap light timer, like this, and connected it to a dim nightlight, set for whatever time I deemed acceptable for getting up. If the light is on, you may get up.