At, on and in: time
at + clock time
in + part of day
on + particular day
at + weekend, public holiday
in + longer period
Clock times: at
- I usually get up at six o’clock.
- I’ll meet you at 4.15. Phone me at lunchtime.
At is usually left out before what time in an informal style.
- What time does your train leave?
Parts of the day: in
I work best in the morning. three o’clock in the afternoon
We usually go out in the evening.
Note the difference between in the night (mostly used to mean ‘during one particular night’) and at night (= during any night).
- I had to get up in the night.
- I often work at night.
In an informal style, we sometimes use plurals (days etc) with no preposition.
- Would you rather work days or nights?
We use on if we say which morning/ afternoon etc we are talking about, or if we describe the morning/afternoon, etc.
- See you on Monday morning.
- We met on a cold afternoon in early spring.
- I’ll ring you on Tuesday. My birthday’s on March 21st.
- They’re having a party on Christmas Day.
- In an informal style we sometimes leave out on.
- I’m seeing her Sunday morning.
We use plurals (Sundays, Mondays etc) to talk about repeated actions.
We usually go and see Granny on Sundays.
Public holidays and weekends: at
We use at to talk about the whole of the holidays at Christmas, New Year,
Easter and Thanksgiving (AmE).
We’re having the roof repaired at Easter.
But we use on to talk about one day of the holiday.
- Come and see us on Christmas Day.
- What are you doing on Easter Monday?
British people say at the weekend; Americans use on. What did you do at the weekend?
Longer periods: in
- It happened in the week after Christmas.
- I was born in March.
- Our house was built in the 15th century.
- Kent is beautiful in spring.
- He died in 1616.
Other uses of in
In can also be used to say how soon something will happen, and to say how
long something takes to happen.
- Ask me again in three or four days.
- I can run 200 metres in about 30 seconds.
The expression in … ‘s time is used to say how soon something will happen,
not how long something takes. Compare:
- I’ll see you again in a month’s time.
- It’ll be ready in three weeks’ time.
- He wrote the book in a month.
In American English, in can be used in negative sentences, like for, to talk
about periods up to the present.
- I haven’t seen her in years.