What Time Does the Sun Rise Today at Your Latitude and Longitude? (It's Not Noon ± 12 Hours)
Sunrise and sunset times vary by location, date, and time of year. Planning outdoor activities, photography sessions, or astronomy observation requires knowing exact sun times. A sunrise/sunset calculator takes your location and date, then calculates when the sun will rise and set, accounting for your latitude, longitude, and the solar position on that specific day.
What This Calculator Does
A sunrise/sunset calculator takes your location (or coordinates) and a date, then calculates the precise time the sun rises and sets at that location. It displays times in your local timezone and often includes bonus information like the duration of daylight, solar noon (when the sun is highest), twilight times (civil, nautical, astronomical), and the sun's azimuth and altitude angles. This is essential for photographers (golden hour timing), outdoor enthusiasts, agriculture, and anyone planning activities based on daylight.
How to Use This Calculator
Enter your location (city name, coordinates, or address) and select a date. The calculator instantly shows sunrise and sunset times, daylight duration, and often additional data like solar noon and twilight times. Most calculators display results in your local timezone automatically. You can change the date to see how sunrise/sunset times shift throughout the year, revealing the seasonal pattern. Some versions include a visualization showing the sun's path across the sky.
The Formula Behind the Math
Calculating sunrise and sunset requires understanding solar position astronomy.
Key inputs:
The algorithm (simplified):
Step 1: Calculate the day number. Convert the date to the number of days since January 1. April 10 is day 100 of the year.
Step 2: Calculate the solar declination. This is the sun's latitude (north or south of the equator) on a given date. It varies from +23.5° (summer solstice, June 21) to −23.5° (winter solstice, December 21). The calculation uses:
solar_declination ≈ 23.44° × sin(360° × (day_number − 81) / 365)
For April 10 (day 100): solar_declination ≈ 23.44° × sin(360° × 19 / 365) ≈ 9.1° north of equator
Step 3: Calculate the equation of time. This accounts for the difference between solar time (based on the sun's position) and clock time (based on the atomic clock). It corrects for Earth's elliptical orbit and axial tilt. This is a complex polynomial; most implementations use a lookup table or formula.
Step 4: Calculate the hour angle at sunrise/sunset. The sun rises when it reaches a specific position relative to the observer. The hour angle (ω) at sunrise/sunset is:
cos(ω) = −tan(latitude) × tan(solar_declination)
For 40° north latitude and 9.1° solar declination on April 10:
cos(ω) ≈ −tan(40°) × tan(9.1°) ≈ −0.307
ω ≈ 108° (or about 7.2 hours from solar noon)
Step 5: Calculate sunrise and sunset times.
The division by 15° converts hour angle to hours (360° ÷ 24 hours = 15° per hour).
Step 6: Convert to local time. Apply the timezone offset and daylight saving time if applicable.
Our calculator automates this, using algorithms from the Astronomical Almanac or NOAA to ensure accuracy ± a few minutes.
Note: Results are estimates. Actual sunrise/sunset times depend on atmospheric refraction, elevation, and local horizon obstructions. A valley between mountains experiences different sunrise times than a flat plain at the same coordinates.
Photography and Golden Hour: Perfect Timing
Photographers prize the "golden hour", the period shortly after sunrise or before sunset when light is soft and warm. A sunrise/sunset calculator tells you exactly when this happens, so you can schedule shoots accordingly.
Outdoor Recreation and Activity Planning
Hikers, campers, and outdoor enthusiasts use sunrise/sunset times to plan activities. Knowing the sun sets at 8:15 PM helps you schedule a 2-hour hike so you're not caught in darkness.
Agriculture and Farming: Optimizing Crop Growth
Farmers use daylight duration data for crop planning. Some crops need specific day lengths to flower. Longer days near summer trigger flowering in long-day plants; shorter days trigger it in short-day plants.
Tips and Things to Watch Out For
The calculated times assume a flat horizon. If you're in a valley with mountains to the east, the sun rises later than calculated. If you're on a tall hill, it rises earlier. These local effects aren't in the calculation unless you account for local elevation/horizon.
Atmospheric refraction matters. When you see the sun "rising," it's actually below the geometric horizon due to light bending through the atmosphere. Sunrise/sunset calculators typically define these as when the sun's upper edge touches the horizon, accounting for refraction. Results are accurate to ±1-2 minutes.
Daylight saving time can shift displayed times. If DST begins or ends on your target date, the calculator must apply the shift. Most modern calculators handle this automatically.
Twilight times vary by definition. Civil twilight (when the sun is 6° below the horizon) is when artificial lights are typically needed. Nautical twilight (12° below) is when stars appear. Astronomical twilight (18° below) is when all stars are visible. The calculator might show all three or just sunrise/sunset.
High latitudes have extreme sunrise/sunset shifts. Near the Arctic Circle, the sun might not set for months in summer (midnight sun) or not rise for months in winter (polar night). The calculator handles these edge cases, but "sunrise" and "sunset" become meaningless, use twilight times instead.
Location accuracy matters. If your coordinates are off by 10 km, sunrise/sunset times might shift by a few minutes. For precise timing, use accurate coordinates.
Frequently Asked Questions
What time does the sun rise and set today at my location?
Enter your city or coordinates into the sunrise/sunset calculator above, and it instantly shows today's sunrise and sunset times in your local timezone.
What's the longest day of the year (most daylight hours)?
The summer solstice (around June 21), when the sun is farthest north. Use the calculator to see sunrise/sunset times on June 21 at your location, the time span is maximum daylight.
What's the shortest day (least daylight)?
The winter solstice (around December 21), when the sun is farthest south and lowest in the sky. Sunrise is latest, sunset is earliest, resulting in the fewest daylight hours.
How much does sunrise/sunset time change by location?
Latitude has the biggest effect. Moving 1° north or south changes sunrise/sunset time by roughly 4 minutes per degree. Longitude matters only for timezone. At 40° latitude, sunrise varies about 2.5 hours between summer and winter.
What is solar noon?
The moment the sun reaches its highest point in the sky, typically around 12 PM local time (but not exactly, due to the equation of time and timezone offsets).
What is "civil twilight"?
The period when the sun is 6° below the horizon. There's still enough ambient light that artificial lighting isn't strictly necessary. It's roughly 20-40 minutes before sunrise and after sunset, depending on latitude and season.
Why does sunrise time vary more than sunset time?
It's partly due to the equation of time and partly seasonal. The actual variation is similar, but they don't vary symmetrically around solar noon.
How accurate are sunrise/sunset calculators?
Typically ±1-2 minutes, assuming flat terrain and standard atmospheric conditions. Local terrain, elevation, and atmospheric conditions can add ±10+ minutes of variation.
Related Calculators
The Time Zone Converter helps if you want sunrise times in a different timezone. The Date Difference Calculator shows daylight duration between summer and winter solstices. The Countdown Timer lets you count down to sunset or sunrise time. Together, these tools help you understand and plan around the sun's daily and seasonal rhythm.