It’s officially the winter solstice aka the first day of winter (although it’s felt like that for some time now…) aka the shortest day of the year!
In the winter, days feel shorter because the Sun rises later in the morning and sets earlier at night. The North Pole of the Earth is tilted away from the Sun, so we in the northern hemisphere receive less sunlight and it's winter. The winter solstice happens when the Earth's North Pole is tilted farthest from the Sun.
As the Earth moves in its orbit around the Sun, the tilt of the North Pole changes. When the North Pole of the Earth is tilted toward the Sun, we in the northern hemisphere receive more sunlight and it's summer. The day that the Earth's North Pole is tilted closest to the sun is called the summer solstice. This is the longest day (most daylight hours) of the year for people living in the northern hemisphere and is also the day that the Sun reaches its highest point in the sky.
In between, there are two times when the tilt of the Earth is zero, meaning that the tilt is neither away from the Sun nor toward the Sun. These are the vernal equinox (the first day of spring) and the autumnal equinox (the first day of fall). Equinox means "equal." During these times, the hours of daylight and night are equal – both are 12 hours long.
All that to astronomically say, if winter is getting you down, the days get longer from here!
