How to pronounce “intercalation” in English

So you can't actually predict on what day the equinox or the solstice or anything like that would occur.And this required then a process called intercalation, which just means throwing stuff in the middle of the calendar.But it's got lots of letters, so it makes me sound smart, I hope.

Now this meant that in the Greek world, there were innumerable-- basically innumerable calendars that had to be negotiated in some way.But by 450 BCE, attempts had been made to regularize the calendar through intercalation.