What day is the flea market in animal crossing?

It is on the first Saturday of every month and it starts at 6 a.m. (The earliest time an animal will ever be awake) and ends around midnight (the latest time any animal will stay up). If you want to know when the flea market is coming to your town you go up to the lost and found and talk to the police officer and ask about "What's going on" and he will tell the date of when a flea market is coming to your town.