winter vacation; winter holidays
Refers to the winter break, typically around New Year's, for schools and some workplaces.
冬休みは家族と過ごす予定です。
I plan to spend the winter vacation with my family.
冬休みの宿題がたくさん出た。
We got a lot of homework for the winter break.
Winter vacation starts next week.
Winter vacation ended, and school started again.
We went to a hot spring with my family during winter vacation.
I still haven't finished my winter vacation homework.