The question I was supposed to answer was “¿A qué hora es el almuerzo?”. They said it was at 12 pm. So I wrote “El almuerzo es a las doce de la tarde.” But they said it was supposed to be “El almuerzo es a las doce del día.” Shouldn’t both work? I would never use "tarde" for 12 pm. For me "tarde" is always used some time after lunch. The most natural answer here in Spain would be "El almuerzo es a las 12 de la mañana" because we start having lunch after 13pm so we consider 12pm still morning. But technically 12pm is already noon so in other countries "El almuerzo es a las 12 del mediodía" is more correct. This is fine in Spain too and can be used, so you could stick to this answer as the correct one. But I would avoid "tarde" here anyway. On the other one I got wrong, they gave us times and we were supposed to say what time it is. It said 12:00 am. I put “Son las doce de la mañana.” It was corrected as “Son las doce de la noche.” Before this, I thought that de la mañana = anytime in the AM, de la tarde = PM before dark, and de la noche = PM after dark. Is this incorrect? I know that the other ways to say 12 PM and 12 AM are “mediodía” and “medianoche” but why were my answers wrong? I do consider 12 AM night not morning, so I guess de la noche makes sense, however the correct answer for 1:00 AM was “Es la una de la mañana.” Is it not correct to say de la mañana until 1 AM? I think of 1 AM as night as well. You use "de la mañana" after 12 AM but you don't include 12 AM. 12 AM = de la noche 1 AM = de la mañana As a side note. In some countries (Spain, Chile, maybe there are more) we use the 24 hour system and rarely use the AM/PM system when writing. Answer from haitike on reddit.com