Time - at, on, in
A. Preposition Time: at, on, in
a. at for the time of day (e.g. There's a meeting at 2.30 this afternoon / at lunch time.), and at night, at the weekend, at Christmas, at the same day, etc.
b.. on for days and dates (e.g. Many shops don't open on Sundays.)
c. in for longer periods (month/ year/ seasons) (e.g. I visited Italy in July, in spring, in 1994), and in the morning but on Friday morning; in a few minutes/ in six months etc. (e.g. The train will be arrived in a few minutes. (= a few minutes from now)); in ~ to say how long it takes to do something (e.g. I learnt to drive in four weeks. (= it took me four weeks to learn))
d. We do not use at/ on/ in before last/ next/ this/ every (e.g. I'll see you next Friday)
e. In spoken English we often leave out on before days (Sunday/ Monday etc.) (e.g. I'll see you on Friday. or I'll see you Friday)
Time - ~ time, ~ the end
A1. Preposition Time: ~ time, ~ the end
a. On time: punctual, not late. (e.g. The 11.45 train left on time. (= it left at 11.45)). The opposite of on time is late. (e.g. be on time. Don't late)
b. In time (for something/ to do something) = soon enough. (e.g. Will you be home in time for dinner? (= soon enough for dinner)). Can say just in time (= almost too late) (e.g. We got to the station just in time for our train.) The opposite of in time is too late. (e.g. I got home too late to see the game on television.)
c. At the end (of something) = at the time when something ends: at the end of the month; at the end of the film (e.g. I'm going away at the end of January.) Cannot say 'in the end of ~. So cannot say 'in the end of January' or 'in the end of the concert'. The opposite of at the end (of ~ ) is at the beginning (of ~) (e.g. I'm going away at the beginning of January. (not in the beginning))
d. In the end = finally We use in the end when we say what the final results of a situation was. (e.g. We had a lot of problems with our car. We sold it in the end. (= finally we sold it)) The opposite of in the end is usually at first. (e.g. At first we didn't get on very well, but in the end we became good friends.)