Page 254 - English Grammar in Use

Unit
121 at/on/in (time)

A Compare at, on and in:
They arrived at 5 o’clock.
They arrived on Friday.
They arrived in June. / They arrived in 2012.
We use:
at for the time of day
at five o’clock at 11.45 at midnight at lunchtime at sunset etc.
on for days and dates
on Friday / on Fridays on 16 May 2012 on New Year’s Day on my birthday

in for longer periods (months/years/seasons etc.)
in June in 2012 in the 1990s in the 20th century in the past in winter

B We say:

at the moment / at the minute / at present / at this time (= now):
Can we talk later? I’m busy at the moment.
at the same time
Kate and I arrived at the same time.
at the weekends / at weekends (or on the weekend / on weekends in American English):
Will you be here at the weekend? (or … on the weekend)
at Christmas (but on Christmas Day)
Do you give each other presents at Christmas?
at night (= during nights in general), in the night (= during a particular night):
I don’t like working at night. but I was woken up by a noise in the night.

C We say:
in the morning(s) but on Friday morning(s)
in the afternoon(s) on Sunday afternoon(s)
in the evening(s) on Monday evening(s) etc.
I’ll see you in the morning. I’ll see you on Friday morning.
Do you work in the evenings? Do you work on Saturday evenings?

D We do not use at/on/in before last/next/this/every:
I’ll see you next Friday. (not on next Friday)
They got married last June.
We often leave out on before days. So you can say:
I’ll see you on Friday. or I’ll see you Friday.
I don’t work on Monday mornings. or I don’t work Monday mornings.

E We say that something will happen in a few minutes / in six months etc. :
The train will be leaving in a few minutes. (= a few minutes from now)
Andy has gone away. He’ll be back in a week. (= a week from now)
They’ll be here in a moment. (= a moment from now, very soon)
We also use in … to say how long it takes to do something:
I learnt to drive in four weeks. (= it took me four weeks to learn)

on/in time, at/in the end ➜ Unit 122 in/at/on (position) ➜ Units 123–125 in/at/on (other uses) ➜ Unit 127
242 American English ➜ Appendix 7