Why the Shortest Day Is Not the Day With the Earliest Sunset or Latest Sunrise

Many people assume that the shortest day of the year (winter solstice), the earliest sunset, and the latest sunrise all happen on the same day. It makes sense, right? But the reality is a little bit more complicated than that.

In the Northern Hemisphere, the winter solstice, the shortest day of the year, falls around December 21-22. However, the earliest sunset occurs around December 4–12, and the latest sunrise happens around January 2–8. But why?

First, Let’s Talk About the Winter Solstice

The winter solstice is the day when the North Pole is tilted the farthest away from the Sun. On this day, the Sun follows its shortest arc across the sky, giving us the least amount of daylight in the Northern Hemisphere.

But here’s the thing, the solstice isn’t about sunrise or sunset times—it’s about the Sun’s position in the sky.

The Role of Earth’s Tilt and Orbit

Earth’s 23.5-degree axial tilt and its elliptical (not perfectly circular) orbit around the Sun are key players in this drama.

Axial Tilt

This tilt gives us seasons, as different parts of Earth receive varying amounts of sunlight throughout the year.

Elliptical Orbit

Earth doesn’t orbit the Sun at a constant speed. It moves faster when it’s closer to the Sun (perihelion, in early January) and slower when it’s farther away (aphelion, in early July). This uneven speed affects the timing of solar noon—the moment when the Sun is highest in the sky.

When you combine these two factors—the changing speed of Earth in its orbit and the tilt of its axis—you get what astronomers call...

The Equation of Time

Here’s where it gets even more interesting. The "equation of time" is a concept that explains discrepancies between solar time (based on the Sun’s position) and clock time (which assumes the Sun moves at a constant rate and divides the day into equal 24-hour segments). This difference can add up to about 16 minutes throughout the year.

The tilt and elliptical orbit cause solar noon, the moment when the Sun reaches its highest point in the sky, to shift slightly day by day.

During December, solar noon gradually shifts later relative to our clock time. At the same time, the Sun's maximum height is changing—getting lower until the solstice, then higher again. These two effects interact differently before and after the solstice

Earliest Sunset

A few weeks before the solstice (around early to mid-December), they work against each other, giving us our earliest sunset. For the Southern Hemisphere, the earliest sunset occurs in early June.

Latest Sunrise

A few weeks after the solstice (early January), they work together, pushing our latest sunrise later. For locations in the Southern Hemisphere, the latest sunrise occurs in late June/early July.

This is also why sunrise and sunset times don't change at the same rate throughout the year.

Key Takeaways

The shortest day of the year, the winter solstice, isn’t the day with the earliest sunset or the latest sunrise because of two key factors: the Sun’s height in the sky and the timing of solar noon (when the Sun is highest) relative to clock time.

In December, solar noon gradually shifts later each day compared to clock noon. This delay affects both sunrise and sunset times. At the same time, the Sun’s arc across the sky gets shorter, reaching its lowest point on the solstice.

These combined effects mean the earliest sunset happens before the solstice, while the latest sunrise occurs after. The shortest day only marks the lowest Sun arc, not the extremes of sunrise or sunset.

This question pops up every December without fail, and we totally get it—it’s not the easiest concept to wrap your head around. But hopefully, this explanation helps make it all a little clearer!