Sunrise Sunset Calculator by Latitude and Longitude

Sunrise and Sunset Equations:

\[ \text{Sunrise} = 12 - \frac{DL}{2} + \left(\frac{\text{long}}{15}\right) - \frac{EoT}{60} \] \[ \text{Sunset} = 12 + \frac{DL}{2} + \left(\frac{\text{long}}{15}\right) - \frac{EoT}{60} \] \[ DL = \frac{2}{15} \times \arccos(-\tan \phi \tan \delta) \times \frac{180}{\pi} \]

Latitude (φ):

degrees

Longitude (long):

degrees

Solar Declination (δ):

degrees

Equation of Time (EoT):

minutes

Day Length (DL):

Sunrise:

Sunset:

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1. What is the Sunrise Sunset Calculator?

The Sunrise Sunset Calculator estimates the times of sunrise and sunset for a given location and date using latitude, longitude, solar declination, and the equation of time. It's based on astronomical calculations of the sun's position.

2. How Does the Calculator Work?

The calculator uses these equations:

Where:

\( DL \) — Day length (hours)
\( \phi \) — Latitude (degrees)
\( \delta \) — Solar declination (degrees)
\( \text{long} \) — Longitude (degrees)
\( EoT \) — Equation of time (minutes)

Explanation: The equations account for the Earth's tilt, location, and the difference between solar time and clock time.

3. Importance of Sunrise/Sunset Calculation

Details: Accurate sunrise/sunset times are crucial for agriculture, photography, religious observances, outdoor activities, and understanding daylight patterns.

4. Using the Calculator

Tips: Enter latitude (-90 to 90), longitude (-180 to 180), solar declination (-23.45 to 23.45), and equation of time (-20 to 20 minutes). All values must be valid.

5. Frequently Asked Questions (FAQ)

Q1: What is solar declination?
A: The angle between the sun's rays and the Earth's equatorial plane, varying between ±23.45° throughout the year.

Q2: What is the equation of time?
A: The difference between solar time and clock time due to Earth's elliptical orbit and axial tilt, ranging from -14 to +16 minutes.

Q3: Why does longitude affect sunrise/sunset?
A: Because the Earth rotates 15° per hour, locations east/west of your time zone's central meridian will experience sunrise/sunset earlier/later.

Q4: How accurate is this calculator?
A: It provides theoretical values. Actual times may vary due to atmospheric refraction, terrain, and altitude.

Q5: Can I use this for any date?
A: Yes, but you need the correct solar declination and equation of time values for your specific date.