1. What is the Sunrise Sunset Calculation?

The sunrise and sunset calculation estimates the times when the upper limb of the Sun appears on the horizon based on geographic location and date. The calculation depends on latitude and solar declination.

2. How Does the Calculator Work?

The calculator uses these equations:

Where:

• \( DL \) — Day length in hours
• \( \phi \) — Latitude in degrees (-90 to 90)
• \( \delta \) — Solar declination in degrees (-23.5 to 23.5)

Explanation: The calculation accounts for the Earth's axial tilt and the observer's position on Earth to determine when the Sun appears and disappears.

3. Importance of Sunrise/Sunset Calculation

Details: Accurate sunrise/sunset times are crucial for agriculture, photography, outdoor activities, religious observances, and energy management.

4. Using the Calculator

Tips: Enter latitude (-90 to 90) and solar declination (-23.5 to 23.5). Declination varies throughout the year (approximately +23.5° at June solstice, -23.5° at December solstice).

5. Frequently Asked Questions (FAQ)

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

Q2: What is solar declination?
A: Solar declination is the angle between the Sun's rays and the Earth's equatorial plane, ranging between ±23.5° throughout the year.

Q3: Why are sunrise/sunset times different at the same latitude?
A: Local topography, atmospheric refraction, and time zones can affect actual observed sunrise/sunset times.

Q4: What about polar day/night?
A: When latitude + declination ≥ 90°, there's polar day (24h daylight). When latitude - declination ≥ 90°, there's polar night (24h darkness).

Q5: How accurate is this calculation?
A: This provides approximate times. More precise calculations account for atmospheric refraction, elevation, and the Sun's angular diameter.