Hi Andrea,
Oh, you are headed to the best place on earth…or shall I say The Happiest Place on Earth to celebrate a birthday! Let me start off by wishing a very Merry Birthday to you!
What you are referring to in your question was a fantastic birthday campaign that the Disneyland Resort had a few years ago; unfortunately it is not being offered anymore. Currently there is not any birthday specials at the Disney Parks. I like to check the Disney Parks website often for new specials and then the disneyparksblog.com for updates before any Disney Park vacation.
Be sure to stop by Guest Services and tell them you are celebrating your birthday. The Cast Member will give you a free "It's My Birthday" button to wear; you will be sure to get birthday wishes and smiles all day.
Unfortunately, partial-day Theme Park Tickets are not available at this time.
Here are the Theme Park Tickets currently available for Guests.
I hope this helps and that you are having a supercalifragilisticexpialidocious day. Please write me back if you have any more questions planning your pixie-dusted vacation.
chEARs!
~ Lynette