Latin etymology of Spanish "tarde"

Question

In Spanish, the word "tarde" has two different meanings:

1. The part of the day between noon and dusk. Equivalent to the English noun "afternoon".
2. Happening after the due, usual, or proper time. Equivalent to the English adverb "late".

The Spanish Royal Academy states in its dictionary that the word comes from Latin "tarde". But I would like to know which one of both meaning came before. I can find one occurrence of "tarde" as "late" in "Cantar de Mio cid" from 1140, and many occurrences of "tarde" as "afternoon" in texts by Alfonso X the Wise (13th century). This matches what Spanish etymologist Joan Corominas states in his dictionary: the "late" meaning may have come before than the "afternoon" meaning.

Nonetheless, as it seems that both meanings came from Latin "tarde", I would like to know:

• Was the word "tarde" used in Late Latin or Medieval Latin?
• If so, what was its meaning?
• If it already had both meanings, which one of them came first?

I suspect that the "late" meaning came first, as the original verb from which the word was derived was "tardare" (also in Spanish: "tardar") that means "to delay". But I would like confirmation about this.

Answer 1

The "slow" meaning came first.

The Latin adjective is tardus -a -um (with adverb tarde), and its origin is unknown. But it definitely was used for "late" or "slow" in Latin (hence "tardy", "retardation"), and I've never seen it used for "afternoon".

The verb tardāre/tardar is indeed related, but it seems to have come from the adjective, not the other way around.