Hello, Cindy! Thanks for stopping by planDisney and asking your question!
When adding the
Park Hopper option to your tickets, the cost is per ticket, not per day. So, that's why there isn't the option of adding the Park Hopper option to just one day of your two-day ticket. The Park Hopper option is the same flat cost no matter if you purchase a one-day or a five-day ticket. Plus, you'll get the benefit of being able to park hop on both days of your trip!
Park hopping at the Disneyland Resort is so incredibly easy as Disneyland Park and Disney California Adventure Park are mere steps away from each other. And being able to park hop provides ultimate flexibility in planning your days. You can start the day riding all the classic attractions in Disneyland Park, hop over to Disney California Adventure Park for some fun in Cars Land and
Avengers Campus, and then hop back over to Disneyland Park for fireworks!
I hope this helps. Have a great time at the Happiest Place on Earth!
-Linda