This peculiar event occurs at different times depending on which version of Animal Crossing you’re playing.
The times are: Last Friday of April (North America), Last Saturday of April (Europe), 3rd September (Japan), 2nd March (Korea). No matter where you live though, the event plays the same.
On the day, Leif from the Garden Centre will appear in the town plaza. If there are no weeds in town, he will suggest one of three unique Public Works Projects for your town.
If there are weeds in town, he will ask you to pull them all out. Speak to Leif after pulling every weed and he’ll reward you with a random piece of the Weeding Day furniture.
Either way, you can also earn Weeding Day furniture for every 30 weeds you pull from another person’s town. If you want to collect every piece of furniture, you will have to travel a lot, as 8 of the 12 furniture cannot be obtained in your town!
Best you go making friends, huh? (Especially international friends, as you can participate in their Weeding Day on different days.)
Here’s the list of unique furniture: