Translation:The third hour is after the first hour.
It is the third hour after the first hour. This interpretation would actually mean it's the fourth hour.
The third hour is after the first hour. This one sounds to me like someone's about to get caught lying. :D
And there's even a third option. There is a third hour after the first hour. Someone's curious about the system for measuring time. :D
Volgav vitsenanieff nivya kevach varatsach.
A colleague explained to me a little bit about how Duolingo courses are constructed. They have very limited choices on what sentences they can put together, especially at the beginning of the course. All we need to learn here is that "hora" is the nominative and is feminine, and when used in sentences with "post" or "ante" we need to add an m.
So I'm fully aware of how Romans told time in the old days, but how would we use the hora system now. Do we just say that hora means o'clock like they do with "ora" in italian and spanish, or do we stick with the old way where the length of the hour changes depending on time of day and time of year?
Generally, you're a source of goodness, Rae.F, but I fear you are misleading the flock on this one.
For first declension nouns, "-am" is the accusative singular ending and nothing else. It has no other role with first declension nouns. The ablative singular ending for first declension nouns is "Ā" (long "a"):
"Hora" is a first declension noun:
The preposition "post" takes the accusative: http://www.informalmusic.com/latinsoc/prep.html
I agree with Rae.F here. The sentence makes perfect sense both gramatically and syntactically, even though it is a slightly strange thing to say. One might choose to say it otherwise, but this is actially a good way to prepare for how to tell the day of the month Roman style.