First Day Of Winter 2025 Canada Time. The shortest day can occur on december 20, 21, 22, or 23. This marks the date of the winter solstice, which is the first day of astronomical winter for the northern hemisphere.
Click on the date that. The winter solstice marks the shortest day of the year when the north pole is tilted farthest away from the sun, and so the sun is at its lowest elevation in the sky.