Hello Rosalinda,
I’m thrilled to infinity & beyond that you have an upcoming adventure to the Disneyland Resort - even more that you will get to enjoy the parks with your dad! You guys are sure to make magical memories that will last a lifetime.
Unfortunately, the Disneyland Resort does not offer partial day tickets. Your dad will have to pay the full ticket price. However, even with him only attending the evening hours, he is still going to be right in the middle of the magic. Sometimes we take a partial day at the parks so we can enjoy the hotel pool or just catch up on some more sleep.
I recommend you look at the Times Guide to see what the plan of the day is during your visit. With this, you can make a plan to either ride attractions or take a snack break and enjoy a show or parade with your dad.
I hope this helps and that you have a pixie-dusted visit. If you have any more questions, please visit me here and let me know how I can help you plan your magical vacation.
Wishing you magic!
~Lynette