Нужно написать правильный предлог. Помогите пожалуйста.

1) He was born ____ September.
2) I go swimming ___ the weekend.
3) My sister does her homework ___ the afternoon.
4) I don't go out ___ Friday evenings.
5) We went to the concert ___ last week.
6) I woke up ___ midnight.
7) ____ summer he usually stays with his grandparents.
8) My mother was born ___ May 20.
9) We were at home ___ yesterday evening.
10) We get a lot of presents ___ Christmas Day.