We use AT with times: at 5 o’clock - at 11.45 - at midnight - at lunchtime
We use AT in these expressions: at night - at Christmas - at the moment / at present - at the same time - at weekends - at the age of...
We use ON with dates and days: on 12 March - on Friday(s) - on Friday morning(s), on Sunday afternoon(s) - on Saturday night(s), on Christmas Day (but at Christmas)
We use in for longer periods of time: in April - in 1986 - in winter - in the 19th century - in the 1970s - in the morning(s) / in the afternoon(s) / in the evening(s)
In + period of time = a time in the future, e.g. Jack will be back in a week.
In + how long it takes to do something, e.g. I learned to drive in four weeks.
We use during + noun to say when something happens: during the film - during our holiday - during the night, e.g.I fell asleep during the film.
We use for + a period of time: for six years - for two hours - for a week, e.g. I’ve lived in this house for six years. They have been watching TV for two hours.
We use since + a period of time: since April - since 1992 - since 8 o’ clock, e.g. It has been raining since one o’ clock. They’ve known each other since they were at school.