Sure! Here are the correct prepositions filled in for both sections:

**A)** Fill in prepositions of time “AT / IN / ON”

1. **On** Saturday **at** 9 o'clock **in** autumn
2. **In** July **at** Christmas **at** half past two
3. **In** 1984 **on** September 28th
4. **On** Monday morning **in** 1991 **at** Easter
5. **On** Friday **on** August 29th
6. **In** summer **in** winter **on** Thursday afternoon
7. **In** the morning **in** the evening **at** noon
8. **At** midnight **on** Saturday night

**B)** Fill in the blanks with “AT / IN / ON”

1. We always go on holiday **in** summer.
2. My mother usually goes shopping **on** Friday morning.
3. I always do my homework **in** the evening.
4. The circus usually comes to our town **in** spring.
5. Sophia's birthday is **on** May 16th.
6. I usually get up **at** seven o'clock.
7. My favorite television program begins **at** 6:30 **in** the evening.
8. Sometimes it snows **in** winter.
9. My friend's birthday is **in** June.
10. Some birds and animals come out **at** night.