Because two birthdays are better than one: Happy 180th, Chicago!

Calumet 412 wished Chicago a happy 180th birthday this morning. But if you remember the city celebrating its 175th birthday just last year, you’re likely confused.

That’s because the date of birth officially celebrated by the city is March 4, 1837. That’s when Chicago received its first city charter, and it’s the date on our city seal.

Four years earlier, it incorporated as a town, accounting for today’s birthday. The Encyclopedia of Chicago doesn’t specify an exact date for the 1833 town charter—depending on your source, it could be Aug. 5, Aug. 10 or Aug. 12.

Regardless: there’s never a bad time to read up on Chicago’s history and tell the city how good it looks for its age—whether you consider it 176 or 180.