In (at some point in morning/afternoon/evening hours)

By (means at the beginning of morning/afternoon/evening)

During (not specific time or several times in morning/afternoon/evening)

Since (means for the time after morning/afternoon/evening)

Until (before this morning/afternoon/evening)

I’ll finish in the morning.

I’ll be finished by morning.

(not used very much)

Since morning, I have been finishing the project.

Until this morning, I was working on the project.

See you in the afternoon.

I can meet you by tomorrow afternoon.

Let’s have lunch during the afternoon.

I have been thinking about the project since this afternoon.

I thought I could meet you until my plans changed this afternoon.

I eat dinner in the early evening.

Let’s eat by this evening.

We had a long dinner party during the evening.

We have been talking since evening—now it’s late at night.

I’m free until this evening. Then I have to go meet people.

I woke up in the night.

Let’s go by night time.

I woke up twice during the night.

He has been sleeping since 6pm yesterday.

I was working until late at night.