Prepositions of Time

Prepositions of Time (At, In, On)

The prepositions "at," "in," and "on" are regularly used in time expressions. For example:

"At" is used for precise times.

• at 4 o'clock
• at midnight
• at sunrise
• at the moment

"On" is used with days and dates.

• on Sunday
• on Wednesdays
• on my birthday
• on 5 November

"In" is used for months, years, centuries (i.e., long periods)

• in June
• in the winter
• in 2022
• in the 19th century

If you're teaching these prepositions of time, it might be useful to highlight that the order "at," "on," and "in" generally corresponds to short periods (or a highly accurate expression), medium periods (or a fairly accurate expression), and long periods (or an inaccurate expression).

Your Go!

It's your go. Select the correct preposition:

More Examples with "At"

"At" is generally used with a short period or a highly accurate expression:

• The train arrives at 10 o'clock.
• Jane raised her hand at the same time.
• The birds fly to their roots at sunset.

More Examples with "On"

"On" is generally used with a medium period (often a day or a date) or a fairly accurate expression:

• Halloween is on 31 October.
• We have tennis practice on Tuesdays.
• It always seems to rain on New Year's Day.

More Examples with "In"

"In" is generally used with a long period or an inaccurate expression:

• We're going to Croatia in January.
• Albert Einstein was born in 1879.
• The telescope was invented in the 17th century.

These guidelines are quite well-observed. However, there are exceptions, which should be learned as set phrases (or collocations, i.e., words that sound natural when used together).

Set Time Phrases

Here are some set phrases that are not obvious fits for the guidelines presented above.

Set Phrases with "At":

Phrase	Example
at any time	You can visit me at any time.
at dinnertime	Jack will meet you at dinnertime.
at lunchtime	Where are you going at lunchtime?
at night	The vampires come out at night.
at some point	I need to talk to you at some point.
at that time	I was not working there at that time.
at this time	At this time, I cannot say why the contract was cancelled.

Set Phrases with "On":

Phrase	Example
on the hour	The bus comes on the hour.
on time	The train is on time.

Set Phrases with "In":

Phrase	Example
in a few days	Let's meet up again in a few days.
in five minutes	I will arrive in five minutes.
in the afternoon	It is going to rain in the afternoon.
in the evening	In the evening, I normally study.
in the future	Will robots rule the world in the future?
in the morning	The robin always sings loudly in the morning.
in the past	In the past, I owned a horse.

No Preposition

Some set phrases have no preposition.

Set Phrases with No Preposition:

Phrase	Example
a week ago	I was in London a week ago.
a year from now	I wonder what I'll be doing a year from now.
the day after tomorrow	She will meet you the day after tomorrow.
the day before yesterday	I was paid the day before yesterday.
later	See you later.
long ago	Long ago, people lived in these huts.
nowadays	Nowadays, nobody eats the carp in these lakes.
recently	I was in Scotland recently.
soon	I will call you soon.
today	She will sign the contract today.
tomorrow	We're all going to the zoo tomorrow.

The preposition is dropped after the following adjectives:

Adjective	Example
every	I have tennis practice on every Tuesday.
last	We went to Italy in last year.
most	She trains at most lunchtimes.
next	We are working in New York in next month.
this	Where are you going in this spring?

In these examples, the preposition you might have expected based on the time period has been deleted. For example, in the first example, you might have expected "on" because "on" is used with days like "Tuesday." However, when "every" is used, the preposition is dropped.