Calculate Sunrise Sunset Time

Sunrise and Sunset Equations:

\[ \text{Sunrise} = 12 - \frac{DL}{2}, \quad \text{Sunset} = 12 + \frac{DL}{2} \] \[ DL = \frac{2}{15} \times \arccos(-\tan \phi \tan \delta) \times \frac{180}{\pi} \]

Sunrise Time:

Sunset Time:

Day Length:

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1. What is the Sunrise/Sunset Calculation?

The sunrise and sunset times are calculated based on the observer's latitude and the sun's declination. These calculations are fundamental in astronomy, navigation, and various practical applications like agriculture and photography.

2. How Does the Calculator Work?

The calculator uses the following equations:

\[ \text{Sunrise} = 12 - \frac{DL}{2}, \quad \text{Sunset} = 12 + \frac{DL}{2} \] \[ DL = \frac{2}{15} \times \arccos(-\tan \phi \tan \delta) \times \frac{180}{\pi} \]

Where:

\( DL \) — Day length in hours
\( \phi \) — Latitude in degrees (-90 to 90)
\( \delta \) — Solar declination in degrees (-23.5 to 23.5)
12 — Solar noon (middle of the daylight period)

Explanation: The calculation determines when the sun's center crosses the horizon, considering the observer's position on Earth and the sun's position in the sky.

3. Importance of Sunrise/Sunset Times

Details: Knowing exact sunrise and sunset times is crucial for outdoor activities, religious observances, photography (golden hour), aviation, and understanding seasonal changes in daylight.

4. Using the Calculator

Tips: Enter latitude in degrees (-90 to 90), declination in degrees (-23.5 to 23.5). The declination changes throughout the year, reaching maximum values during solstices.

5. Frequently Asked Questions (FAQ)

Q1: Why does the day length vary?
A: Day length varies due to Earth's axial tilt (23.5°) and its orbit around the sun, causing the solar declination to change throughout the year.

Q2: What is solar declination?
A: Solar declination is the angle between the rays of the sun and the plane of the Earth's equator, ranging from +23.5° (June solstice) to -23.5° (December solstice).

Q3: Are these times exact for my location?
A: These are theoretical calculations. Actual times may vary slightly due to atmospheric refraction, elevation, and local topography.

Q4: What about daylight saving time?
A: This calculator provides solar times. You'll need to adjust for your local time zone and daylight saving rules.

Q5: How accurate is this calculation?
A: It's accurate for most purposes but doesn't account for atmospheric refraction which makes the sun appear higher than it actually is.