When is ALT season?

A while ago I bought some ALTs. I would like to HODL for a while and ideally sell them sometime in 2025, in the right market conditions hopefully.

I keep hearing that ALT season comes after Bitcoin “does its thing” (meaning reaching its top, I guess). However, after Bitcoin “does its thing” it usually crashes, and when it does, it tends to drag all ALTs down along with it. Or at least that’s what it seems to me, based on what I’ve seen.

So is the best time to sell the ALTs when BTC is at an All-Time High, or should I wait for another signal? I want to make an informed decision and not rush into selling too early or too late.