Hello, Priscilla!
Thank you very much for stopping by! Since you're coming from another country for such a fantastic adventure, I'll share my best advice to help you find the dates you need, okay?
Currently,
Guests need a park ticket and a park reservation to visit the Disneyland Resort on any given day. This means that you won't be able to use May 15 tickets to enter the theme parks on May 19 or May 20. The key here is to find a way to secure reservations for May 19 and May 20, and I think I have a plan that may help you.
The best strategy for you is to book a room at the
Disneyland Resort hotel for those dates. This idea may work because Disney has a separate park reservation inventory for Guests staying inside the Disneyland Resort. This logic applies to
Disney's Grand Californian Hotel & Spa, the
Disneyland Hotel, and
Disney's Paradise Pier Hotel, and they're all great alternatives.
I can currently see park reservation availability for May 19 and May 20 for Guests staying at the Disneyland Resort hotels, so this could apply to you if you move fast. To check availability when reading this answer, simply
look at this calendar. The key to making this work is to book your Disneyland Resort hotel room using your Disneyland account and buy your tickets.
I will be crossing my fingers for you, Priscilla! May the magic be with you,
Julie