at
●   times: at 8pm, at midnight, at 6:30
       ●   holiday periods: at Christmas, at Easter
       ●   at night
       ●   at the weekend
       ●   at lunchtime, at dinnertime, at breakfast time
on
       ● days: on Monday, on my birthday, on Christmas Day
       ● days + morning / afternoon / evening / night: on Tuesday morning
       ● dates: on the 20th of June
in
       ●   years: in 1992, in 2006
       ●   months: in December, in June
       ●   decades: in the sixties, in the 1790s
       ●   centuries: in the 19th century
       ●   seasons: in winter, in summer
       ●   in the morning, in the afternoon, in the evening
no
prep
       ● next week, year, month etc
       ● last night, year etc
       ● this morning, month etc
              ● every day, night, years etc
              ● today, tomorrow, yesterday
Click on the following link to practise PREPOSITIONS OF TIME:
https://www.perfect-english-grammar.com/preposition-exercises.html
If something is contained inside a box or a wide flat area, we use ‘in’:
in the newspaper                                      in a house
in a cup                                              in a drawer
in a bottle                                           in a bag
in bed                                                in a car
in London                                             in England
in a book                                             in a pub
in a field                                            in the sea
in my stomach                                         in a river
If something is on a line or a horizontal or vertical surface, we use ‘on’:
on the table                                on the wall
 on the floor                                on the window
 on my face                                  on a plate
 on the page                                 on the sofa
 on a chair                                  on a bag
 on the river                                on a t-shirt
 on the ceiling                              on a bottle
 on a bike                                   on his foot
If something is at a point, (it could be a building) we use ‘at’:
 at the airport                                   at the door
 at the table                                     at the bus stop
 at the cinema                                    at the top
 at the bottom                                    at the pub
 at the traffic lights                            at the front
 at the back                                      at school
 at university                                    at the window
 at the hospital                                  at the piano
Here are some more common ones that don't really fit:
   ●   on TV
   ●   on the bus
   ●   on a train
   ●   on a plane
   ●   on the radio
   ●   at home
   ●   at work
Click on the following link to practise PREPOSITIONS OF PLACE:
https://www.perfect-english-grammar.com/prepositions-of-place-exercise-1.html
https://www.perfect-english-grammar.com/prepositions-of-place-exercise-2.html