The fourth line in the first stanza contains an idiom which may not be familiar to you.

It means only that the two friends talked all day until the sun set in the West, and still talked on after that.

Tennyson has used the same Greek thought in a verse of his poem, "A Dream of Fair Women," where Cleopatra says, "We drank the Libyan sun to sleep." The Greek author of the above poem was the great poet Callimachus, and the English translator does not think it necessary even to give the name, as he wrote only for folk well acquainted with the classics.

He has another short translation which he accompanies with the original Greek text; it is very pretty, but of an entirely different kind, a kind that may remind you of some Japanese poems.

It is only about a cicada and a peasant girl, and perhaps it is twenty-four or twenty-five hundred years old.
A dry cicale chirps to a lass making hay, "Why creak'st thou, Tithonus ?" quoth she.