The afternoon is the part of each day that begins at noon or lunchtime and ends at about six o'clock, or after it is dark in winter.
You refer to the afternoon of the present day as this afternoon.
You refer to the afternoon of the previous day as yesterday afternoon.
You refer to the afternoon of the next day as tomorrow afternoon.
If you want to say that something happened during a particular afternoon in the past, you use on.
If you have been describing what happened during a particular day, you can then say that something happened that afternoon or in the afternoon.
If you are talking about a day in the past and you want to mention that something had happened during the afternoon of the day before, you say that it had happened the previous afternoon.
If you want to say that something happened during the afternoon of the next day, you say that it happened the following afternoon.
If you want to say that something will happen during a particular afternoon in the future, you use on.
If you are already talking about a day in the future, you can say that something will happen in the afternoon.
If you are talking about a day in the future and you want to say that something will happen during the afternoon of the next day, you say that it will happen the following afternoon.
If something happens or happened regularly every afternoon, you say that it happens or happened in the afternoon or in the afternoons.
If you want to say that something happens regularly once a week during a particular afternoon, you use on followed by the name of a day of the week and afternoons.
In informal English, you can use afternoons without 'on' or 'in'.
If you have mentioned an exact time and you want to make it clear that you are talking about the afternoon rather than the early morning, you add in the afternoon.
| Noun | 1. | afternoon - the part of the day between noon and evening; "he spent a quiet afternoon in the park"daylight, daytime, day - the time after sunrise and before sunset while it is light outside; "the dawn turned night into day"; "it is easier to make the repairs in the daytime" midafternoon - the middle part of the afternoon |
| 2. | afternoon - a conventional expression of greeting or farewellfarewell, word of farewell - an acknowledgment or expression of goodwill at parting greeting, salutation - (usually plural) an acknowledgment or expression of good will (especially on meeting) |