At 2, In, On (Time)
At, in and on are prepositions of time. When talking about clock times (ex. 5 a. m.), we use at. ex. You have an appointment at 3 p. m.
However, to talk about clock times, at is not usually used in questions. ex, What time is the party? (NOT: At what time is the party?)
When talking about days and dates, on is used. ex. Let’s meet on Tuesday.
On is also used for weekends and during is often used for the full period of a holiday. ex. What did you do on the weekend?
When talking about parts of the day (except night) and long periods of time, in is used. ex. I visited the hospital in the morning. ex. The school year starts in September. ex. The party is at night.
In is also used when talking about how soon something will happen and how long something happens. ex. We will see you in a week. ex. I can come in 15 minutes.
Preposition of time + time word or phrase
Ex: at 5 p. m.; on Sunday morning; in 10 minutes
There are some expressions that do not use prepositions of time. At/on/in are not usually used in expressions of time before next, last, this, that, any, each, every, some, all. ex. See you next week. (NOT: See you on next week.)
Questions beginning with what/which + time expression are also often used without prepositions of time. ex. What time is the meeting? (NOT: At what time is the meeting?)
In (place) on (place) at (place)