___ is also used for specific time. (midday, night, dinner time etc.)
at
We use ____ with time of the day.(the morning, the evening etc.)
in
I always get up _____ 8 a.m.
at
We get together ____ Christmas day.
on
Used for talking about special day.(birthday, New Year, Christmas etc.)
on
I often get sleepy ____ the afternoon.
in