Here on the East Coast that allows generator use all public places seem to have the 8AM-10AM and then again from 4PM to 7-8PM generator hours. Never after 8PM or before 6AM the next morning... Even the Natl Forest areas do this same thing. Just now some Natl Forest areas are allowing 8AM to 8PM but one needs to check first...
It is very hard to find a public dispersed camping area around here where anything goes.
This was the main reason I beefed up the batteries to run all the things I want to run when camping off grid and only use my 2KW Generator from 8AM each morning to get from the 50% charge state to the 90% charge state so I can do this all over again for the next day/night run off my batteries... I usually get away with running my 2KW generator for three hours starting at 8AM. Every now and then I get the word to follow the rules. It kinda hard to hear my 2KW Honda very far away from my camping spot...
This is what I do when camping off-grid here on the East side of the US...
Roy Ken