We use ‘at’ with:
Specific times of day:
The movie starts at 10:45.
He always has a sandwich at lunchtime.
She heard a strange sound at midnight.
General short periods (night, weekend):
What are you doing at the weekend? [British English]
*It’s cold at night recently. [‘at night’ is general, while ‘in the night’ is more specific]
Short holiday periods:
I ate too much at Christmas.
Are you going anywhere at New Year?
NOTE: We usually drop ‘at’ with the question ‘What time …?’
(At) What time are you going (at)?
We use ‘on’ with:
Single days of the week:
I’m planning to go to Tokyo on Wednesday morning.
He goes to the gym (on) Mondays. (= every Monday)(‘on’ can be dropped)
* I usually go shopping on weekends. Are you doing anything on the weekend? [American English]
Dates:
My birthday is on the 24th of April.
I have a meeting in Osaka on September the 12th.
Special dates:
Do you usually go out for dinner on your birthday?
What did you do on your wedding anniversary?
Are you having turkey on Christmas Day?
We use ‘in’ with:
Parts of the day:
I’m busy in the morning, but free in the afternoon and evening.
*I heard a sound in the night. (a specific part of the night)
Longer periods of time; Weeks, months, seasons, years, centuries:
Will you go anywhere in Golden Week?
He often goes skiing in January and February.
I go swimming in (the) summer, but not in spring.
I bought my car in 2021.
In the 21st century, technology is advancing at an astonishing pace.
In the future people will live on Mars. In the past that idea was science fiction.
An action that happens within a period of time:
He completed the test in 30 minutes.
The plane will land in an hour.
I’ll see you in (three months’ time/three months).
NOTE: ‘At the end’ or ‘in the end’?
‘At the end’ refers to the point in time that something ends.
At the end of the play, the actors took a bow.
‘In the end’ suggests ‘finally’
In the end I decided to quit my job. I thought about it for three months.
NOTE: ‘At the beginning’ or ‘in the beginning’?
‘At the beginning’ refers to the point in time something starts.
At the beginning of the lesson, we check our homework.
‘In the beginning’ suggests ‘initially’ and contrasts to later
In the beginning, my job was really hard, but now I’m used to it.
Time expressions without at, on, in
We don’t normally use ‘at’, ‘on’, or ‘in’ with time expressions beginning with before, after, during, each, every, next, last, some, this, that, these, those, one, any, all:
I watch TV every evening.
She drinks coffee after dinner.
What are you doing this evening?
It was cold all winter.
These days it’s very humid.
