Summer 2021 officially comes to a close Wednesday at around 3:30 p.m. with the autumnal equinox. Just like its springtime partner — the vernal equinox — there are roughly 12 hours of sunlight and 12 hours of darkness everywhere on the planet.

But that’s just one way of defining the season. There’s also the meteorological summer, which spans from June 1 to August 31, and ended this year nearly a week before Labor Day, which is — of course — the unofficial end of summer.

So between all these calendars, when, exactly, are the dog days of summer?

That’s a question we here at The Curiosity Desk spent a portion of our hottest season seeking an answer to. And while the inspiration for this phrase can indeed be found in our galaxy, it was coined a long time ago and far, far away.

WATCH: What (And When) Are The Dog Days Of Summer?

If there is something you've been itching to know more about, email The Curiosity Desk or send in your question below. Edgar might just dig up the answer in a future episode. For more from The Curiosity Desk, follow Edgar B. Herwick III on Twitter and subscribe to the GBH News YouTube Channel.