Prepositions of time are the ones that allow you to discuss a specific time period such as a date on the calendar, one of the days of the week, or the actual time when something happens.
Ramesh was born in October.
She goes to the park on Sundays.
She wakes up at 5:00.
My school starts at 8 AM.
In England, it often snows in December.
Do you work on Mondays?
‘In’ is used for months and years, ‘on’ for days and dates, and ‘at’ for times.
in March / August / 2018
on Friday / Tuesday / December7th
at5:30 / 1 o’clock / half past nine
We can use ‘on’ for special days and ‘at’ for special times also.
on his birthday / New Year’s Day / the last day of college
at midnight / bedtime / lunch time
We say… We don’t say…
She had lots of fun on her birthday. (NOT She had lots of fun in her birthday.)
We don’t watch TV at lunch time. (NOT We don’t watch TV on lunch time.)
We will go to America in April.(NOT We will go to America on April.)