Is it correct to say: I will see you at the Christmas dinner or I will see you at Christmas dinner

I am a native English speaker and was recently checking some work before it got sent out to our company. I am unsure as to whether it is grammatically correct to say:

"I will see you at the Christmas dinner" or "I will see you at Christmas dinner".

Could anyone shed some light on this please?

Because you are referring to a specific dinner, the article should be included.

See also this answer, which states:

The definite article "the" is used... to refer to a specific entity known to the reader

A similar question about dates was asked and a more detailed explanation was given, but I think the same logic applies here: https://english.stackexchange.com/a/258177/204043