Preposition of time

AT 

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…

ON

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)

IN 

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.

DURING

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.

FOR

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.

SINCE

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.