Prepositions often confused:
On, At, In. (Time.)
✖️Don’t say: My uncle will arrive at Saturday.
✔️Say: My uncle will arrive on Saturday.
✖️Don’t say: I usually get up on seven o’clock.
✔️Say: I usually get up at seven o’clock.
✖️Don’t say: She goes for a walk at the afternoon.
✔️Say: She goes for a walk in the afternoon.
(1) Use “on” with the days of the week or month: on Friday, on March 25, on New Year’s Day
(2) Use “at” with the exact time: at four o’clock, at dawn, at noon, at sunset, at midnight.
(3) Use “in” with a period of time in April, in winter, in 1945, in the morning
Also: at night and by day
Arrive at, not to:
✖️Don’t say: We arrived to the village at night.
✔️Say: We arrived at the village at night.
Note : Use “arrive in” with countries and large cities: Mr Smith has arrived in London. (Or New York, India, etc.)