## Day and Night

Puzzle. The length of the day today in Boston is the same as the length of the coming night tonight. What is the total length of both?

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1. #### Konstantin Knop:

Is length of night = “the time between the sunset and the next sunrise” or “the time between end and start of astronomical twilights”?

2. #### tanyakh:

Between sunset and sunrise.

3. #### Mike G.:

I’m tempted to take the easy solution and notice that it didn’t specify the length of the coming night _in Boston_, so it can be pretty flexible đź™‚

4. #### Mike G.:

Couldn’t resist looking for the harder answer. How fuzzy can equality be? If we do +/- 1 minute, then March 17 (day) and March 17-March 18 (night) look like a pretty good match, at about 11:59 each, for a total length of 23:58.

https://www.timeanddate.com/sun/usa/boston?month=3&year=2019

For a more exact equality, I’d have to fire up Mathematica and hope it’s got a sunrise/sunset data set…

5. #### RoyG:

My brain keeps thinking â€ś12 hours, it is probably wrong!â€ť But it is the only length that makes sense, or â€śinfinitesimallyâ€ť close to 12 hours, so MikeG is probably right.

6. #### tanyakh:

Hint: if the day is exactly the same as the next night, when is the equinox?

7. #### kitsu:

i don’t geet what most people are talking about. however, a day+ night is always 24 hours, right, if they are distinctly partitionaed?