On the phone they said it was simply the total of purchase transactions in a calendar year.

(In this case I’m speaking of Amex Delta Reserve but I assume they measure the same way.)

That doesn’t square with my previous experience. If I recall, Mileage Boosts only occurred once the purchase was made, a statement date passed and the bill was paid. I’m in the mid $50,000’s with my spend and not sure I will hit 60K in time.