also: クリスマスイヴ · クリスマス・イブ · クリスマス・イヴ
Christmas Eve
Refers to the evening or entire day of December 24th, often associated with romantic dates and family gatherings in Japan.
I'm going to dinner with my boyfriend on Christmas Eve.
The children open their presents on Christmas Eve.
I spent a quiet Christmas Eve with my girlfriend.
I'm planning to go on a date with him on Christmas Eve.