What are the rules for Prepositions of Time?

3 rules for Prepositions of Time (at, on, in)

The main rules to remember are:

Rule 1 for Prepositions of Time ‘At’

At = an exact point in time

Examples: at lunchtime, at midnight, at noon, at the end of the conference, at three o’clock.

  • I arrive at 1 o’clock.
  • The meeting is at lunchtime.
  • We will finish at dinner-time.

Rule 2 Prepositions of Time ‘On’

On = a day or a date

Examples: on my birthday, on Monday, on 24th March, on Independence Day, on the first day of the semester.

  • The match is on Wednesday.
  • The shops are closed on Independence Day.
  • The conference starts on May 1st.
  • The registration is on the first day of the semester.

Remember: it is on Independence Day, on Christmas Eve, on Easter Monday, BUT at New Year, at Christmas and at Easter.

Rule 3 Prepositions of Time ‘In’

In = a period of time

Examples: in the afternoon, in January, in spring, in 2015.

  • We met in 2011.
  • In summer, we go to our summer house.
  • I usually drink tea in the afternoon.
  • The school term starts in September.