Today. So I would need to renew by May 20, 2020.
The pass is in the form of an e-ticket you can activate via your email confirmation or on your smart phone. I did not see there was any other option to receive the pass. DW and I will be activating the pass when we get out to Anaheim a week from today.
Between the access to both parks on our reservation days and access to
Disneyland and California Adventure on two different "Good-to-Go" days of our trip, the Flex Pass has already paid for itself. In fact, per day, it's already less expensive to use than any hopper/1-park-per-day option, and we're just getting started!
After becoming a former AP holder after getting priced out of the market five years ago, I can't wait to use the dining/merchandise discounts again. My only regrets are lack of parking as an add-on and the Christmas/New Year's blackout dates, but you truly can't have everything at this price.