English (UK) · Prepositions

Time: at, on, in

English uses three prepositions for points in time, from the smallest to the biggest:

at for clock times and a few fixed expressions: at eight o'clock, at half past six, at noon, at midnight, at night, at lunchtime, at sunrise, at the moment.
on for days and dates: on Monday, on Sundays, on the 5th of May, on New Year's Day. A day plus a part of the day also takes on: on Friday evening, on Sunday mornings.
in for longer periods: months (in July), years (in 2004), seasons (in winter), decades and centuries (in the 1980s, in the twentieth century) and parts of the day (in the morning, in the afternoon, in the evening).

Watch the exceptions: at night, but in the morning and in the middle of the night; in the morning, but on Monday morning.

Examples

The concert starts eight o'clock.Show answer

The concert starts at eight o'clock.

The meeting is Tuesday.Show answer

The meeting is on Tuesday.

I was born 1998.Show answer

I was born in 1998.

We often go skiing winter.Show answer

We often go skiing in winter.

My cat sleeps all day and plays night.Show answer

My cat sleeps all day and plays at night.

The shop opens nine o'clock.Show answer

The shop opens at nine o'clock.

I go swimming Saturdays.Show answer

I go swimming on Saturdays.

Her birthday is May.Show answer

Her birthday is in May.

I always drink coffee the morning.Show answer

I always drink coffee in the morning.

We have lunch noon.Show answer

We have lunch at noon.