Time Prepositions

In 

I will travel in December

She will practice swimming in Summer

He wrote a book in 2004

He drove his car in May

They watched TV in winter

On

They were married on June 15

My birthday is on May 13th

She will travel on her birthday

We will make a bonfire on Saturday

She is going to a party on Friday

At

I go to the cinema with my friends at 3 o'clock

They ride bikes on the weekend

The boy gave him a dog at Christmas

We went for a walk at midnight

We went swimming at 6 o'clock