English grammar: Prepositions of time

What this grammar point covers

Prepositions of time are words we use in English to say when something happens. They help us talk about dates, times, and periods.

When to use it

Use prepositions of time to say when something happens, like a specific time, day, date, month, or period.

Key forms

• at + clock times (at 5 o'clock)
• on + days and dates (on Monday, on July 4th)
• in + months, years, parts of the day, long periods (in June, in 2020, in the morning)

Examples

Tips

• Use 'at' for exact times (at 8:00, at midnight).
• Use 'on' for days and dates (on Friday, on January 1st).
• Use 'in' for months, years, and longer periods (in 2010, in summer).

Exceptions and edge cases

• We say 'at night', not 'in the night'.
• We say 'on the weekend' (American English) or 'at the weekend' (British English).