If you need a line in the sand for how late is “too late,” it’s illegal to sound your car horn between 11:30pm and 7:00am, so I don’t think it’d be unreasonable to expect a bit of hush from neighbours at those times also.
Personally I use 11pm as my self-imposed cutoff for turning off the amp and suchlike, if I’m noisy past that time then it’s unintentional. Seems to work, I’ve not had any complaints. Though I suppose they could be talking about me on a web forum somewhere.
Is it actually causing you a problem beyond “gosh, that’s a bit late”? It doesn’t sound like it’s keeping you awake if you’re contemplating starting a load of laundry. If it is, have a quiet word as they’re probably unaware (or can hear you clomping about and assume it’s fine as you’re still up). If not, well, so what?