I have a small 3 year-old walk into my bedroom ~6am every day and jump up and down on the end of the bed saying, I want to have breakfast/watch Bob the Builder/brush the baby's teeth..
Funnily enough, this perfect alarm-clock never fails to wake me up!
That sounds like how I wake up on the weekends, except mine is also normally shouting, "The sun is up!" He never seems to realize that I know, but don't care that the sun is up.
Some days it's the 3 year old, some days the 5 year old, some days the 1 year old. In the rare event that none of them wake up before 7:30, I wake up by then on my own. Sleeping in has long been situationally impossible; I now find it biologically impossible as well.
Funnily enough, this perfect alarm-clock never fails to wake me up!