Prepositions of Time
IN
Months :
My birthday is IN December
Years
The Mexican Revolution began IN 1910
Centuries
He died IN the 16th century
Seasons
We go to the beach IN summer
Days of the week
I go to the gym ON monday
Dates
We celebrate mother's day ON may 10th
Parts of the day
I eat eggs IN the morning
AT
Hours
She sees you AT 3 o'clock
Festivities
I eat turkey AT Christmas