Time Prepositions: at, on and in
We use at, on and in to say when something happens. The choice depends on the range of the time expression:
- at → a specific point in time
- on → a day or date
- in → a longer period of time
At = a point in time
Use at for exact times and short, specific moments.
-
The bus leaves at 10 o'clock.
Come at 5:30. -
She isn't here at the moment.
Owls hunt at night. - Common expressions: at noon, at midnight, at sunrise, at bedtime, at Christmas
On = a day or date
Use on with days, dates and special named days.
-
We play football on Saturdays.
I was born on 4 March. -
We meet on New Year's Day.
I got a present on my birthday. -
Day + part of the day:
See you on Friday night.
The train arrives on Monday morning.
In = a longer period
Use in with periods that are longer than a day.
-
Parts of the day:
in the morning, in the afternoon, in the evening -
Months, seasons and years:
in July, in winter, in 2025 -
Longer periods:
in the past, in the future, in the 1990s
Important exceptions
We do not use a preposition before: this, last, next and every.
- I saw him last week. (not
in last week) - Are you working this evening?
- We meet every Monday.
- See you next year.
Other useful differences
-
In + period of time = after that time from now:
The train leaves in ten minutes. -
At night = night in general:
I don't like driving at night. - In the night = during one particular night:
A noise woke me up in the night. -
At the beginning/end of = a position in an event:
There is a test at the beginning of the lesson. -
In the beginning = at first
In the end = finally
It was difficult in the beginning.
In the end, we chose Spain. - On the weekend = American English
- At the weekend = British English
Quick reference
-
at → exact time / point
at 7 o'clock, at midnight -
on → day / date
on Monday, on 5 June -
in → longer period
in July, in 2025, in winter
