Prepositions of Time

There are three prepositions of time:


‘At’ is used for precise times:

At ten o’clock.

At 10.30am.

At the moment/present/same time.

At sunrise/sunset/noon/dinnertime/bedtime/dusk/dawn.

Note: At night is a standard expression that is an exception in this case.


‘In’ is used for months, years, decades, centuries, and long periods of time:

In January.

In 1991.

In the 70s.

In this century.

In the Dark Ages.

Note: In the morning(s)/afternoon(s)/evening(s) are standard expressions that are exceptions in this case.


‘On’ is used for days and dates:

On Wednesday.

On Friday.

On the 10th of January

On Christmas.

Note: ‘on’ is also used when you specify the day followed by the part of the day. For example on Wednesday mornings.