1. What is FAA Twilight?

FAA twilight refers to the periods of time before sunrise and after sunset when the sun is below the horizon but there is still some natural light. The FAA defines different types of twilight (civil, nautical, astronomical) for aviation operations.

2. How Does the Calculator Work?

The calculator estimates twilight times based on sunset times:

Where:

• Sunset — Official sunset time for the location
• Adjustment Factor — Time difference based on twilight type and location

Explanation: The actual calculation involves complex astronomical formulas based on the sun's position relative to the horizon.

3. Importance of Twilight Calculation

Details: Twilight times are crucial for aviation operations, photography, and outdoor activities. The FAA uses these times to determine when aircraft must have certain lighting.

4. Using the Calculator

Tips: Enter accurate sunset time, location, and date. Select the appropriate twilight type for your needs.

5. Frequently Asked Questions (FAQ)

Q1: What are the different types of twilight?
A: Civil (sun 0-6° below horizon), Nautical (6-12°), and Astronomical (12-18°).

Q2: Why does twilight duration vary?
A: Duration depends on latitude and time of year - longer at higher latitudes.

Q3: How accurate is this calculator?
A: For precise aviation use, consult official FAA publications or astronomical tables.

Q4: Does the FAA have different rules for twilight?
A: Yes, the FAA defines specific lighting requirements during twilight periods.

Q5: Can I use this for photography planning?
A: Yes, but professional photographers may need more precise golden/blue hour calculations.