Timing for Meteor?

Can anybody tell me when the damage of Meteor is calculated?
For maximum damage you want your Convention of Elements on the correct element, you want to stand in the ring of your followers’ Occulus Ring, etc.
Question is, when is the right time to do so? When you cast your meteor (or trigger it via the set bonus of Tal’s), or when it actually hits?
As these two events are some time apart this may make quite the difference in your timing and positioning.

Thank you!

Update: Did some testing with just Convention of Elements equipped and a completely stripped down wizard without weapon, crit chance, etc.
The relevant moment is when the meteor strikes. Answered my own question. :slight_smile: