I recall Fr. Patrick Henry Reardon on a podcast pronouncing it Kal-KEE-don. Can't bring myself to say it that way. Kal-si-DOH-nee-an sounds best
See the above post of mine.
It's sorta like putting up with the Greek "experts" around here who want to make St. Paul or even Homer speak like their grandpa. (When someone derides "Erasmian Greek", you know to stop listening.)
It's sorta like asking how to pronounce angina
Some of my docs say: an-ˈjī-nə
The others are the new and improved doctors.
Strange they don't apply the same principle to another word.
Let's call the whole thing off.
Sorry for my poor IPA, Isa, Jeremy, et al.