Hello Eileen and thank you for returning to the Disney Parks Moms Panel with yet another great question about your dear families rapidly approaching post-Christmas trip to Walt Disney World Resort.
I can just imagine how excited you and your loved ones must be feeling about visiting
The Magic Kingdom Park for the very 1st time and I know it'll be practically perfect for you in every way!
On your behalf I've double checked the current Disney Parks schedule for the 28th and 29th December 2015 via this
Calendar for Magic Kingdom Park link and I'm happy to say
Mickey's Once Upon a Christmastime Parade looks to be indeed scheduled for each afternoon at 3.30pm.
However, because things update and evolve all the time at Walt Disney World Resort I recommend picking up a
Park Guide Map as you enter any Disney Theme Park just to be certain of all current parade and showtimes for the duration of your visit.
Also for your further information be sure to check out this jolly
Holidays at Walt Disney World Resort link!
Have a great Disney day.
~ Jane