The prepositions on, in and at are also used with different times.
For Example: We use 'in' with year and Month. India got independence in 1947.
Christmas is celebrated in December.People wear garments made of wool in winter.
When you look at the above examples, you will find that 'in' is used with a large unit of time.
On: It is used with a specific day or a date. Example: Christmas is celebrated on 25th of December every year. We get up a little late on Sunday. Please don't use in Sunday.
At: It is used when you mention the exact time. For example: My college begins at 10.00 AM and gets over at 4.00 PM.
Some prepositions of time are used as phrases. They are in the morning, in the evening, at noon, at night.
I will visit Delhi in December this year.
I visited Mumbai in 2009.
Rani goes to the temple on Friday.
Mary's birthday is on Wednesday. I need to buy her some gifts.
Raj will had a party on 15th July, 2010
Please meet me at 5.00 PM.
The manager asked his assistant to fix up an appointment with his customer at 9.00AM.
In summer, people usually don't go out at noon.