Official Start Of Winter 2025 Calendar. Ending on 28 (or 29 during a leap year) february. Winter 2025 starts on saturday, december 21st in the northern hemisphere, with the first day of winter being the shortest daylight day of the year with the earth's axis having reached its furthest tilt away from the sun and begins to change directiion back.

Graded coursework (including but not limited to tests, exams, quizzes) is not permitted. The following dates are sorted chronologically, beginning in january of 2025.