It's a royal tradition.

This year, like every year, Kate Middleton and Prince William alongside other members of the royal family will be opening and exchanging gifts on Christmas Eve instead of Christmas Day. The royals apparently chose December 24 due to their German heritage. In Germany, gifts are opened on Christmas Eve and so, the Cambridge family and company are joining this tradition. Speaking to the Express, former royal chef Darren McGrady said:

"The royals are of German descent so they weave in German traditions to their celebrations. "After afternoon tea, they open gifts on Christmas Eve, as is the German tradition."

This will be Prince Louis' first Christmas and so, he'll be joining his siblings in opening their presents on Christmas Eve - whereby all the gifts are placed on "trestle tables" to be opened at "teatime", reveals the royal website.

Prince Louis was born on April 23, 2018.

On Christmas Day however, the royals don't lay around eating Christmas leftovers, they're dressed and up early to out the door to attend St Mary Magdalene Church for a service. This outing gathers crowds who wait outside the church on December 25 in a hope to spot the royals leaving the grounds. Last year Meghan Markle joined Prince Harry despite not getting married until May of this year. Therefore, this will be Meghan's second Christmas alongside Harry and her first Christmas as the Duchess of Sussex. Many believe Meghan's mother, Doria Ragland will travel to the UK this winter to join Meghan and the royal family.

Harry and Meghan, Christmas Day 2017.

This will also be Meghan and Harry's last Christmas as a twosome as Meghan is due to give birth to the couple's first child in Spring 2019.