Prepositions of time test

Prepositions of time test. Choose the right prepositions in, on or at to complete the following sentences.
Chris was born 1985.
I didn't go to school Monday.
I could see the stars night.
I like watching TV the evening.
They got married April.
They never go out Sunday evenings.
We often have a short holiday Christmas.
What are you doing the weekend?
We were ill the same time.
She got married 15 April 1987.
I got up 7 o'clock this morning.
I often go to the beach summer.
He isn't here the moment.
I'll send you the money the end of the month.
Where will you be Christmas Day?
Hurry up! The train leaves five minutes.
Goodbye! I'll see you a few days.
I went to bed midnight.
The writer was born 18th century.
The concert is 24 April.