Hey there Jovi,
Welcome to planDisney and thank you for your question! I'm so happy to hear you're considering gifting theme park tickets - I'll make sure to send you a P.O. box so you can send some my way too while you're at it!
All kidding aside, this is such a special gift idea and I'm glad to help!
When purchasing
theme park tickets through the Disneyland Resort website, you will need to input a date for a
theme park reservation. However, these are easily modified later in the
My Plans hub of the Disneyland Resort website. If this is the route you're planning on going to buy the tickets then I would recommend selecting the furthest out date for a park reservation.
Once you gift the tickets, the recipient will then need to link the tickets to their
Disneyland Resort mobile app. To do that, they will want to select the menu button in the app (the three horizontal lines), then "My Tickets & Passes." Next, they'll tap "Link Tickets & Passes" and input the ticket ID or scan the barcode. Once that's completed then they should be able to adjust the park reservations for the date(s) they plan to attend the parks.
Thanks again for your question, Jovi, and I hope you have a magical day,
Greg