"The restaurant opens in February."
Translation:Il ristorante apre a febbraio.
Found these on the web: http://www.rocketlanguages.com/italian/learn/italian-prepositions/
It sure would be nice if Duolingo would shed some serious light on what the major differences between "a" and "in" are. I still haven't been able to figure that out on my own. One thought, thought: could it be as simple as that you use "a" before months beginning with a consonant and "in" before those beginning with a vowel??
Both work, but here's a link to some nuances: https://www.thoughtco.com/italian-vocabulary-italian-calendar-months-4087628