We use at with times:
at 5 o’clock – at 11.45 – at midnight – at lunchtime
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)
Tom usually gets up at 7 o’clock.
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:
Jack will be back in a week.
The train will leave in a few minutes.
In + how long it takes to do something:
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
I fell asleep during the film.
We met a lot of interesting people during our holiday.
We use for + a period of time:
for six years – for two hours – for a week
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
It has been raining since one o’ clock.
They’ve known each other since they were at school.
We use until/till to say how long a situation continues:
Let’s wait until it stops raining.
I stayed in bed until half past nine.
FROM – TO
We use from – to + beginning and end of a period:
Last evening we watched TV from 5 to 8 o’ clock.