Prepositions of Time - In / At / On
IN
Use 'in' months and years and periods of time:
- in January
- in 1978
- in the twenties
Use 'in' a period of time in the future:
- in a few weeks
- in a couple of days
AT
Use 'at' with precise time:
- at six o'clock
- at 10.30
- at two p.m.
ON
Use 'on' with days of the week:
- on Monday
- on Fridays
Use 'on' with specific calendar days:
- on Christmas day
- on October 22nd
IMPORTANT NOTES
in the morning / afternoon / evening - at night
We say in the morning, afternoon or evening BUT we say 'at night'