Example

at
(a time)

"I got to work at 8.00 this morning."

on

(a day)

"I'll see you on Tuesday."

on

(a date)

"I have an appointment on the 31st."

in

(a month)

"My birthday is in June"

in

(a year)

"I was born in 1959"

in

(the morning)

"I get up in the morning."

in

(the afternoon)

"I have lunch in the afternoon."

in

(the evening)

"I go home in the evening."

at

(night)

"I go to bed at night."

in

(a season)

"It usually snows in the winter