in on and at

Like you can see I keep going with expressions or words I learnt and attract attention to me
Today is time for “in” “at” or “on”
They used then like you can see down here:

In a minute
In two days
In August
In summer
In 1971

At seven o’clock
At morning
At noon

On Monday
On Holiday

Sit on a chair
Sit at this table