Neither rain, nor snow, nor dark of night...

What’s the origin, attribution, and source text of the phrase “Neither rain, nor snow, nor dark of night…”?

I know this much: it has something to do with the mail service. So no need to repeat that. I know it has nothing to do with “it was a dark and stormy night.” I hope we can avoid going off on those tangents.

The phrase comes from the inscription which can be found on the main post offices in New York and Washington, DC, which says:

According to the USPS Website,

So there ya go.

Never mind, I found it. It’s Herodotus writing about the Persian mail system.

Source: Herodotus, translation. A.D. Godley, vol. 4, bk. 8, v. 98, pp. 96–97 (1924).
variant: Not snow, no, nor rain, nor heat, nor night keeps them from accomplishing their appointed courses with all speed. (Book 8, Ch. 98)
Paraphrase: “Neither snow, nor rain, nor heat, nor gloom of night stays these couriers from the swift completion of their appointed rounds” ”
Source: Appears carved over entrance to Central Post Office building in New York City.
Historically, Persian King Xerxes had sent a message home to Persia stating that the Greeks had destroyed his navy off Salamis in the year 480 B.C.E.
Source: George Stimpson, A Book About a Thousand Things, pp. 69–70 (1946).

Simulpost! Sorry about that. This always happens to me.