Latest month at which scheduled Retaliation begins

[Docent]

Hello!
At https://www.ufopaedia.org/index.php/Alien_Retaliation there is such a table.
Interested in the last line (Latest month at which scheduled Retaliation begins) - are these dates tied to the standard start date of the game (January 1, 1999)? Or is it just + 14, 13, 12, 11, 10 months to the start date of the current game? What if my game starts in 2021? Can I somehow correct these dates?

[Meridian]

it's + 14, 13, 12, 11, 10 months

you can change it in missionScripts.rul

[Docent]

Thank you!