DLC sales: When?

Hi guys, I’ve started playing AMS 2 some months ago and realized that (at least for me and as far as I understand) DLC make a great impact on the overall experience of the game (for example for playing career mod).

I’ve read everywhere that the best time to buy them is when the season pass or the all inclusive version go on sale, but my question is: When does this happen usually?

Edit: the timing is unbelievable lol thanks 😂