Fill in the gap with one suitable preposition of time

fill in the gap  with one suitable preposition of time.
1. i'll see you___________sunday, april1.
2. we'll arrive___________5o'clock _________15september
3. it often rain__________may
4.what do you usually do________the weekend?
5.they often go out for dinner________sunday evening
6.they got married_____________december1996
7.i saw him___________19988.
8.do you often give each others persents_________christmas day
10. when did you meet him?_____________lunch to day
11. it often rains__________october in viet nam
13 i don't know but i'm going to go tocollege__________september this year
14.do you want to watch the sky__________sunset?
15.sure and i'd like to walk__________sunrise,too.