Prepositions of Time

Basic examples of prepositions of time include: at, on, in.

For days and dates we use the preposition on.

We go to the sanctuary on Sundays.
Christmas is on December 25th.

For times, night and holidays, use the preposition at.

Families often argue at Christmas time.
I work faster at night.
She is going to stop working at 7pm.

For times of day, months, seasons, years and centuries we use the preposition in.

I don't eat anything in the morning.
It’s always cold in January.
Halloween is in the fall.
I started in 1987.
It happened in the 18th century.