Whether the sun rises earlier in the winter depends on the specific time of the season. Many people mistakenly believe that the latest sunrise and the earliest sunset both occur on the Winter Solstice, the day with the least amount of daylight. This confusion stems from the non-uniform movement of the sun across the sky and how we measure time. While the Solstice marks the shortest day, astronomical mechanics cause the specific times of sunrise and sunset to shift independently.
Separating Sunrise and Sunset Timing
The idea that the Winter Solstice (around December 21st) dictates the latest sunrise and earliest sunset is a common misconception. In reality, the timing of these two events separates around the Solstice. The earliest sunset typically occurs a couple of weeks before the Solstice, often in early to mid-December, depending on latitude. For instance, at 40° North, the earliest sunset is generally around December 8th.
Conversely, the latest sunrise of the year occurs well after the Winter Solstice, usually in early January. At 40° North latitude, the latest sunrise is observed around January 5th. This means that for several weeks in late December, the day lengthens slightly because the sun is setting later and rising later. Although the total daylight is shortest on the Solstice, the independent shift of sunrise and sunset times means the earliest morning light does not immediately follow the shortest day.
The Role of the Equation of Time
This separation in timing is caused by the Equation of Time (EOT), which measures the difference between time kept by a sundial (apparent solar time) and time kept by a uniform clock (mean solar time). Our clocks assume every day is exactly 24 hours. However, the actual time it takes for the sun to return to the same position—an apparent solar day—varies throughout the year. The EOT is caused by two main astronomical factors that combine to make the apparent solar day longer than 24 hours around the Winter Solstice.
The first factor is the Earth’s axial tilt, or obliquity, which is about 23.4 degrees. This tilt causes the sun’s apparent path to move north and south, affecting its speed across the sky. The second factor is the Earth’s elliptical orbit, meaning the planet’s speed changes as it orbits the sun. The Earth moves fastest when it is closest to the sun (perihelion), which occurs shortly after the Winter Solstice in early January.
When the Earth moves faster in its orbit, the sun appears to move faster against the background stars, lengthening the apparent solar day. This faster motion, combined with the axial tilt effect, causes solar noon—the moment the sun reaches its highest point—to occur progressively later by clock time around the Solstice. This continuous delay in solar noon pushes both the sunrise and sunset times later, explaining why the latest sunrise occurs in January instead of December.
The overall result is a slight mismatch between our uniform clock time and the sun’s actual position. This discrepancy is most pronounced from mid-November to early February, when the apparent solar day is longer than 24 hours by several seconds. This longer solar day delays both the sunrise and the sunset times as measured by a clock. The date of the earliest sunset is when the sun’s seasonal path shift is finally overcome by this clock effect.
Daylight Saving Time and Perceived Winter Timing
While the Equation of Time is the astronomical mechanism, the public’s perception of winter timing is also influenced by Daylight Saving Time (DST). When DST ends in the fall, clocks are set back an hour. This non-astronomical shift makes the sunset seem dramatically earlier overnight, often occurring before the end of the workday.
This sudden, artificial change can amplify the feeling that afternoons are disappearing too quickly, confusing the subtle, gradual effects of the Equation of Time. DST only affects the numerical reading on the clock face; it does not alter the actual amount of daylight hours or the underlying astronomical mechanics governing sunrise and sunset. The transition out of DST makes the evenings seem instantly darker, compounding the natural seasonal progression toward shorter days.