Here are the correct prepositions of time to fill in the blanks:

1. We are going to a concert **on** Saturday.
2. My mother usually comes home **at** a quarter to seven.
3. I will see you **in** September.
4. Our new school year starts **in** autumn.
5. There can be a lot of rain **in** July and August in my hometown.
6. This year my birthday is **on** Sunday the 11th.
7. I hate studying **at** night. My best work is done **in** the morning.
8. We first met each other **in** the winter of 2018.
9. Shakespeare was born **in** 1564.
10. I never have bread **at** dinner time.
11. If we arrive **at** 4 o'clock in the afternoon, what will we do?
12. My grandfather died **at** the age of 75.
13. What did you buy for your son **on** his first birthday?
14. What would you like to do **in** the future?
15. I'm only free **on** weekends.