"This year has three hundred and sixty-six days."

Translation: Tento rok má tři sta šedesát šest dnů.

[thomasmarsh]

Shouldn't "letos" also be accepted in place of "tento rok"?

[AgnusOinas]

If you said "Letos má 366 dnů", the immediate question that pops into a native speaker's head is: "Who has 366 days this year?" :)

[endless_sleeper]

Nope, letos is an adverb.

[jarauh]

Is it possible to use "let" as the subject? Or does it have to be "rok"?

[AgnusOinas]

No, "let" is the genetive form of "summers". It's used rather metonymically for "X years" (X let = X roků) where X is greater than 4. But for a single "year", you can only use "rok".

"Léto" (one summer) really does not have 366 days ;)

[jarauh]

Ah, I did not get the connection from "let" to "léto". Indeed, a 366-day summer would have been great, in particular this year.