Welcome to planDisney, Maria Teresa! No matter the length, a trip to Walt Disney World is always a magical idea.
The minimum purchase period for tickets is
two days from Europe. Should you wish to secure tickets ahead of your trip, this is still the best option.
If one day is all you can spend in the magic, an alternative would be to wait until you are in the States to buy your ticket. Once on US soil, you can log into your
My Disney Experience account and purchase a one-day Standard Ticket or choose to add on the Park Hopper perk (which means you can visit more than one Park on the day). I recommend booking before the day of your visit, rather than purchasing tickets at the gate, to avoid any potential disappointment. Especially as December is a popular time of year at Walt Disney World.
As time is of the essence on your adventure, you may also like to consider
Disney Genie+ Service or Individual Lightning Lanes (or both) on the day of your visit. They provide access to shorter wait times for many of Walt Disney World's top attractions.
A final suggestion that may be of interest is buying tickets for
Mickey's Very Merry Christmas Party at Magic Kingdom Park - the closest running dates to your arrival are 12 and 14 December. Other dates are available for this jolly event, which promises all the festive Disney magic one could wish for.
Maria Teresa, I hope this information helps you enjoy all the magical moments at Walt Disney World. If you need anything further ahead of your trip, I'd love to help, Louise.