Prepositions of Time

Prepositions of Time: at, in, on





We use: * at for a PRECISE TIME * in for MONTHS, YEARS, CENTURIES and LONG PERIODS * on for DAYS and DATES
at
in
on

PRECISE TIME
MONTHS, YEARS, CENTURIES and LONG PERIODS
DAYS and DATES

at 3 o`clock
in May
on Sunday

at 10.30am
in summer
on Tuesdays

at noon
in the summer
on 6 March

at dinnertime
in 1990
on 25 Dec. 2010

at bedtime
in the 1990s
on Christmas Day

at sunrise
in the next century
on Independence Day

at sunset
in the Ice Age
on my birthday

at the moment
in the past/future
on New Year`s Eve

Look at these examples:
I have a meeting at 9am.
The shop closes at midnight.
Jane went home at lunchtime.
In England, it often snows in December.
Do you think we will go to Jupiter in the future?
There should be a lot of progress in the next century.
Do you work on Mondays?
Her birthday is on 20 November.
Where will you be on New Year`s Day?
Notice the use of the preposition of time at in the following standard expressions:
Expression
Example

at night
The stars shine at night.

at the weekend
I don`t usually work at the weekend.

at Christmas/Easter
I stay with my family at Christmas.

at the same time
We finished the test at the same time.

at present
He`s not home at present. Try later.

Notice the use of the prepositions of time in and on in these common expressions:
in
on

in the morning
on Tuesday morning

in the mornings
on Saturday mornings

in the afternoon(s)
on Sunday afternoons

in the evening(s)
on Monday evening

When we say last, next, every, this we do not also use at, in, on.
I went to London last June. (not in last June)
He`s coming back next Tuesday. (not on next Tuesday)
I go home every Easter. (not at every Easter)
We`ll call you this evening. (not in this evening)
Pham Ha