Daylight Hours Calculator by Location and Date

Enter your latitude, longitude, and a date to calculate daylight hours, sunrise and sunset times (UTC), solar noon, solar declination, and more.

Created by Luis GonzalezLast updated: May 9, 2026

How to Use This Calculator

1
Enter Latitude
Input the latitude in decimal degrees. Positive values are North, negative values are South (e.g., 40.71 for New York City).
2
Enter Longitude
Input the longitude in decimal degrees. Positive values are East, negative values are West (e.g., -74.01 for New York City).
3
Select the Date
Choose the specific date for which you want to calculate the daylight hours.
4
Review Daylight Data
The calculator will display the total daylight hours, sunrise, sunset, solar noon, and other relevant astronomical details for your specified location and date.

Example Calculation

A planner in New York City (Latitude 40.71°, Longitude -74.01°) needs to know the exact daylight hours, sunrise, and sunset on the summer solstice, June 21, 2024, for an outdoor event.

Latitude

40.71 °

Longitude

-74.01 °

Date

2024-06-21

Results

15h 5m

Tips

Plan Outdoor Activities

Use this tool to precisely plan outdoor events, construction work, or photography sessions, ensuring optimal lighting and sufficient daylight. For example, a construction crew might need at least 10 hours of daylight.

Understand Seasonal Changes

Observe how daylight hours change dramatically with latitude and season. Near the equator, hours are consistent (around 12h), while near the poles, they vary from 0 to 24 hours.

Adjust for Local Time

Remember that sunrise and sunset times are given in UTC. You'll need to adjust for your local time zone and any Daylight Saving Time to get your exact local sunrise/sunset.

Pinpointing Sunlight: Your Daylight Hours by Location and Date

The Daylight Hours Calculator by Location and Date precisely determines the duration of daylight, alongside sunrise, sunset, and solar noon for any specified geographic coordinates and calendar date. This advanced tool is invaluable for meteorologists, photographers, event planners, and anyone requiring accurate solar data for planning and analysis. By leveraging precise astronomical models, it helps understand the varying light conditions throughout the year, from the longest summer days to the shortest winter ones, even accounting for specific dates like the summer solstice on June 21, 2024.

Why Accurate Solar Data Matters for Planning

Accurate solar data, including daylight hours, sunrise, and sunset times, is critical for numerous practical applications beyond general curiosity. For construction projects, it informs work schedules and the availability of natural light, impacting productivity and safety. In agriculture, it helps determine optimal planting and harvesting times, aligning with crop growth cycles. Photographers depend on it for "golden hour" and "blue hour" planning. Furthermore, understanding the precise solar declination is vital for optimizing solar panel efficiency, ensuring panels are angled correctly to maximize energy capture throughout the year. This precision allows for informed decisions that can save time, resources, and enhance outcomes.

The Astronomical Model Behind Daylight Calculations

The Daylight Hours Calculator uses a sophisticated astronomical model to determine the sun's position relative to a given location and date. This involves calculating the solar declination, which is the angle of the sun's rays relative to the Earth's equator, and the hour angle, which represents the angular displacement of the sun east or west of the local meridian.

Solar Declination = 23.45° × sin(toRad((360 / 365) × (Day of Year - 81)))
cos(Hour Angle) = (cos(90.833°) - sin(Latitude) × sin(Declination)) / (cos(Latitude) × cos(Declination))
Daylight Hours = (2 × Hour Angle) / 15

The constant 90.833° accounts for atmospheric refraction, ensuring the calculation determines when the sun's upper limb is truly visible. This model accounts for the Earth's axial tilt and orbital position.

💡 Understanding how geographical factors influence daylight is key. For another climate-related calculation, our Lifted Index Calculator can help predict atmospheric stability and thunderstorm potential.

Calculating Solstice Daylight in New York: A Practical Example

Let's calculate the daylight hours for New York City (Latitude: 40.71°, Longitude: -74.01°) on June 21, 2024, the summer solstice.

Input: Latitude: 40.71°, Longitude: -74.01°, Date: 2024-06-21.
Day of Year: June 21, 2024, is the 173rd day of the year (2024 is a leap year).
Solar Declination: Approximately +23.43°.
Hour Angle Calculation: Using the formula with Latitude 40.71° and Declination 23.43°, the hour angle (H) is calculated to be approximately 113.16°.
Daylight Hours: Daylight Hours = (2 × 113.16°) / 15 = 15.088 hours This translates to 15 hours and 5 minutes.
Sunrise/Sunset (UTC): The calculator then uses the Equation of Time and longitude to determine precise UTC sunrise and sunset times.

The primary result shows 15 hours and 5 minutes of daylight, reflecting the longest day of the year for this Northern Hemisphere location.

💡 Accurate weather and climate data is crucial for many applications. For understanding how atmospheric conditions affect performance, our Humidity Effect on Ballistics Calculator can show its impact on projectile trajectories.

Weather-Climate Benchmarks for Solar Irradiance

Solar irradiance, directly related to daylight hours, is a critical benchmark in weather and climate science. The National Renewable Energy Laboratory (NREL) provides extensive data on solar resource availability across regions, often expressed in kilowatt-hours per square meter per day (kWh/m²/day). For instance, in the contiguous United States, average daily solar irradiance ranges from about 3 kWh/m²/day in cloudy northern regions during winter to over 7 kWh/m²/day in sunny southwestern deserts during summer. These figures correlate directly with daylight duration and intensity. Arctic regions experience periods of 24-hour daylight (midnight sun) or 24-hour darkness (polar night) for several months, while equatorial regions maintain a consistent ~12 hours of daylight year-round, with minimal seasonal variance. These benchmarks are fundamental for energy planning and climate modeling.

How Meteorologists Interpret Daylight Hours

Meteorologists use daylight hours data as a foundational input for weather forecasting, climate modeling, and seasonal analysis. They look at the total duration of sunlight to predict daily temperature ranges, as longer daylight periods allow for more solar heating, leading to higher daytime temperatures and potentially more significant diurnal temperature swings. In winter, shorter daylight hours contribute to lower average temperatures. Daylight data also helps in understanding the energy budget of the atmosphere and oceans, influencing phenomena like sea breeze development and the formation of convective clouds. For climate scientists, long-term trends in daylight hours, combined with solar declination, are crucial for tracking seasonal shifts and assessing the impacts of climate change on ecological systems and agricultural cycles.

Frequently Asked Questions

How are daylight hours calculated based on latitude and date?

Daylight hours are calculated using astronomical formulas that consider the Earth's tilt, its orbit around the sun, and the observer's latitude and date. Key elements include the solar declination (the sun's angular distance north or south of the equator) and the hour angle at sunrise/sunset. These factors determine how long the sun remains above the horizon, with higher latitudes experiencing more extreme seasonal variations in daylight. Longitude primarily affects the local time of sunrise/sunset, not the duration.

What is solar noon and how does it differ from clock noon?

Solar noon is the exact moment when the sun reaches its highest point in the sky at a particular location, directly halfway between sunrise and sunset. It differs from clock noon because clock noon is based on standardized time zones, which average solar time over a wide longitudinal band. Local solar noon can vary significantly from clock noon due to your precise longitude within a time zone, the Equation of Time (Earth's elliptical orbit and axial tilt), and Daylight Saving Time adjustments. It's the true midpoint of daylight.

How do latitude and longitude impact daylight calculations?

Latitude profoundly impacts daylight duration, with higher latitudes experiencing greater seasonal variation, from midnight sun to polar night. Near the equator, daylight hours remain consistently close to 12 hours year-round. Longitude, on the other hand, primarily affects the *timing* of sunrise, sunset, and solar noon in local clock time, as it determines your position within a time zone relative to the prime meridian. It does not significantly alter the *total duration* of daylight for a given date.