1. What is a Solar Time to Local Time Calculator?

Definition: This calculator converts solar time (sun-based time) to local standard time (clock time) accounting for longitude differences and the equation of time.

Purpose: It helps astronomers, navigators, and solar energy system designers synchronize solar observations with standard time.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( LT \) — Local standard time (hours)
• \( LST \) — Local solar time (hours)
• \( STL \) — Standard meridian longitude (degrees)
• \( LOL \) — Local observer longitude (degrees)
• \( EOT \) — Equation of time (minutes)

Explanation: The formula accounts for both the longitude correction (4 minutes per degree difference) and the equation of time (which varies throughout the year).

3. Importance of Time Conversion

Details: Accurate conversion between solar time and local time is crucial for solar panel alignment, sundial calibration, and astronomical observations.

4. Using the Calculator

Tips: Enter solar time in hours (0-24), longitudes in degrees (-180 to +180), and equation of time in minutes. Results are given in 24-hour format.

5. Frequently Asked Questions (FAQ)

Q1: What is the equation of time?
A: It's the difference between apparent solar time (sun position) and mean solar time, caused by Earth's elliptical orbit and axial tilt.

Q2: How do I find my standard meridian longitude?
A: It's typically 15° × your time zone number (e.g., 0° for GMT, -75° for EST, +120° for Philippine Time).

Q3: Why 4 minutes per degree?
A: Earth rotates 360° in 24 hours → 15°/hour → 4 minutes/degree (60 minutes ÷ 15 degrees).

Q4: What if my result is negative or >24?
A: The calculator automatically adjusts to 24-hour format (e.g., -1.5 becomes 22.5, 25.5 becomes 1.5).

Q5: How precise is this calculation?
A: Very precise for most applications, though atmospheric refraction can cause ±1 minute variation.