Prepositions:
Time with In-On-At


  1. Month, year, season, century
    Use IN
    Nobody enjoys swimming in Lake Michigan in January.
    Even in summer most adults are reluctant to swim in the lake.

  2. Day of the week
    Use ON or no preposition
    We used to study ESL on Tuesdays and Thursdays.
    I hope you can meet me Monday at the Willow Room.

  3. Specific date (both month and day or day only)
    Use ON
    Albert Einstein was born on March 24, 1889.
    They finished that job on the 5th and then left town.

  4. The morning, the evening, the afternoon
    Use IN
    Night
    Use AT
    Most students prefer to attend class in the morning.
    If I take a nap in the afternoon, I probably won't be able to get to sleep at night.

  5. Specific hour of the day or night (including noon and midnight)
    Use AT
    The children wake up at 6:30.
    I will need the car at seven o'clock to drive to Milwaukee.
    Some people believe that ghosts walk at midnight.

Special Expressions
In/On/At with the word "time"

on time at the correct time, punctually
I like to get to my classes on time.
in time early enough to do or get something
She arrived in time to get a good seat.
at times occasionally, from time to time
She daydreams in class at times.
at the time the time when something happened
They were in France at the time of the riots.
at a time in a group, together
They let people enter the room two at a time.

A. Staben
CLC Writing Center