SP: To add the mod to an existing SINGLEPLAYER game, do the following:

In the main menu, Instead of clicking "Continue", click "Load", then bottom right click "More", then "Chose mods" and activate the mod. Use the same procedure to remove the mod.


SP and MP:
How to find out what day it is and set proper day range in Sandbox Variable settings:

1. Enable debug mode in sandbox variables.

2. Start the game, note what the current date (DaysPassed) is. It will be displayed VERY clearly on screen.

3. Stop the game, go back into sandbox variables and set a startdate (Days before...) and a stop date (Days until...) that is appropriate for the current date (DaysPassed). What is appropriate is up to you.

4. Disable debug mode in the sandbox variables.

5. Start playing.