“why are contractors at a DC public school mowing grass at midnight?”

“Dear PoPville,

As I write this, I can still hear the mowers, weedwackers and leaf blowers …. why are contractors (anywhere) but especially at a DC public school (Raymond Elementary) mowing grass at midnight? It’s Sunday night, now after 12:15 and they are still out there – wouldn’t local noise ordinances cover this? They ended up stopping around 12:40am, still… pretty late for that kind of noise.”