Why don't we get more daylight faster after the winter solstice?
The article explains that while the winter solstice marks the shortest day of the year, the rate of daylight increase is not immediately rapid due to the elliptical shape of Earth's orbit and the axial tilt. Around the solstice, the Sun's apparent movement along the horizon is at its slowest, causing the change in daylight hours to be gradual at first before accelerating in the weeks following.
Background
- The winter solstice (in the Southern Hemisphere, around June 21) is the shortest day of the year — the day with the fewest daylight hours. After that date, days gradually get longer. But many people notice that the change seems surprisingly slow at first, especially around sunrise times.
- This is due to the "analemma" effect: Earth's orbit is slightly elliptical, and its axis is tilted. These factors mean that the earliest sunset (or latest sunrise) doesn't align exactly with the solstice itself. In midsummer, the Sun's path across the sky changes most slowly near the solstice, so the shift in daylight minutes is tiny in the days immediately after.
- The article explains the geometry: sunrise and sunset times move asymmetrically around the solstice because of the mismatch between solar time (based on the actual Sun) and clock time (based on an average "mean Sun"). So while total daylight is increasing, the change is initially concentrated at one end of the day, making it feel slower than expected.