mn is so black and white.
It is all about context. Who your neighbours are, what time they get up, where you live. how noisy your child is etc etc.
In principle, I would agree with keeping the noise down until 9am.
But my nieghbour ont he left is a postie, he used ot let his dog out for a wee before work, and she would often bark when she did. At 4am.
He did his best to keep her quiet, but he had to leave for work, and she needed a wee before he left her for his shift. That's life isn;t it?
Most people have double glazing and unless you live in a very quiet road, traffic noise will start getting going fomr about 8.
One neighbour 4 houses down has kids that shriek and scream when they are in the garden, which is horrible at any time of day. Other people's kids are out playing early, but just normal voices and play noises.
There really isn't a blanket rule. I'd rather have kids voices than music at any time. Other prefer the opposite.
But to the poster who said her dd was on a trampoline at 8 am on a Saturday. If you were my neighbour I would be serioulsy unimpressed. BOING BOING BOING at 8am on a Saturday. Inconsiderate and bloody horrible.