Since or In

The tense that is used with the word “since” must be either the present perfect or present perfect continuous, because it tells us when something started in the past and indicates it is continuing now.

Examples:

I have been waiting since 7 o'clock.
I have known him since January.
The plant has been operating since July 2020.

Incorrect:

The company entered into a media contract since late 2Q21.
We expect sales will increase following the start of the government’s budget disbursement since April 2024.

“In” refers to when an action or event happened in the past but does not indicate if the action is still continuing at present.

Correct:

The company entered into a media contract in late 2Q21.
We expect sales will increase following the start of the government’s budget disbursement in April 2024.