8 am I reckon.
We live in an apartment and there's a clause about noise. No intrusive noise between 11 pm and 7 am. It doesn't differentiate between days. But, by unspoken consensus, on weekends we all try to be quiet till 8.
After that, well people have lives to live, stuff they need to get done, kids also have things they need to do, like play, run, get about and not be silent.