Most people notice that the sun rises later in winter, earlier in summer, and sets in the opposite pattern. The reason why sunrise time changes daily is simple: Earth's axis is tilted by about 23.5 degrees relative to its orbit around the sun. This tilt, combined with our planet's elliptical orbit, causes the length of daylight to shift continuously throughout the year.
The Earth's Tilt Is the Main Cause
Earth's axis points toward a fixed direction in space (roughly toward Polaris, the North Star). As Earth orbits the sun, the Northern Hemisphere leans toward the sun in June and away from it in December. This changes the angle at which sunlight hits your location, altering the sun's path across the sky.
At the summer solstice (around June 21), the sun reaches its highest point at noon, giving the longest day and the earliest sunrise. At the winter solstice (around December 21), the sun is lowest, and the day is shortest. The rate of change in sunrise time is fastest around the equinoxes (March 20 and September 22) and slowest near the solstices. You can see the daily change with our interactive tables, which show exactly how many minutes the sun shifts each morning.
Why It's Not a Perfectly Equal Shift
If Earth's orbit were a perfect circle and its axis had no tilt, sunrise would occur at the same time every day. But two factors break that symmetry:
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Orbital eccentricity: Earth's orbit is slightly elliptical (oval-shaped). In early January, Earth is closest to the sun (perihelion) and moves fastest in its orbit. This makes the solar day slightly longer in January, delaying sunrise by a few minutes relative to clock time. In July, Earth is farthest (aphelion) and moves slower, so sunrise times shift less.
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Axial tilt: Even if the orbit were circular, the tilt alone would cause sunrise to vary by about 14 minutes over the year. The combination of tilt and eccentricity produces the "equation of time," which means the sun is not at its highest point at exactly noon every day.
How Latitude Affects the Change
Your location on Earth dramatically influences why sunrise time changes. Near the equator, sunrise varies by only about 30 minutes across the year. At 60° north (Stockholm, Helsinki), the difference can be several hours between summer and winter. At the Arctic Circle, there are days when the sun never rises (polar night) or never sets (midnight sun).
The relationship between latitude and daylight is not linear. The same latitude north or south of the equator produces mirrored patterns—when it is summer in the north, it is winter in the south. For a deeper explanation of how your location matters, read our article on latitude and daylight.
Why Sunrise and Sunset Don't Change by the Same Amount
You might notice that sunrise shifts faster than sunset in some seasons, and vice versa. This is because the change in daylight length is split unevenly between morning and evening. Around the summer solstice, for example, the sunrises hold steady (changing by only seconds per day) while sunsets continue to shift later. Around the winter solstice, sunsets become stable while sunrises move later.
The exact pattern depends on your latitude and the time of year. To see how this works for a specific city, check Tokyo's daily sun times, which show the exact minute-by-minute shifts for each season.
The Role of Time Zones and Daylight Saving Time
Human timekeeping adds another layer. While the astronomical reasons for changing sunrise times are fixed by Earth's motion, the times you see on a clock depend on your time zone's offset from UTC. If you live at the western edge of a time zone, you might see a 5:30 AM sunrise, while someone at the eastern edge sees 6:30 AM on the same day.
Daylight saving time shifts everything by one hour in spring and fall. After the spring transition, sunrise jumps an hour later on the clock, even though the actual sun position is the same as the day before. This explains why, in many regions, sunrise times change not just daily but suddenly by 60 minutes twice a year.
How We Calculate the Exact Times
The precise moment of sunrise and sunset depends on three things: your geographic coordinates, the date, and the local horizon. Our algorithms account for atmospheric refraction (which bends sunlight and makes the sun appear about 0.57 degrees higher than it really is), the observer's elevation, and the standard definition of sunrise (when the upper edge of the sun's disk appears on the horizon).
These calculations are based on the Jet Propulsion Laboratory's ephemeris data, which models the positions of the sun and Earth with high accuracy. For the mathematical details, see our article on how the times are calculated.
The daily change in sunrise and sunset is not random—it follows predictable astronomical rhythms tied to Earth's tilt and orbit. Every morning, the sun rises a little earlier or later than the day before, with the largest shifts happening around the equinoxes and the smallest around the solstices. Understanding the reason why sunrise time changes helps you plan your days more effectively, whether you are a photographer chasing golden hour light or someone simply curious about the sky above you.