Basic Usage

This watch uses solar position calculations to determine true north. The red arrow points toward north when properly calibrated.

Daytime Operation (6 AM - 6 PM)

• Simply follow the red arrow tip to find true north
• For increased accuracy, activate the correction feature
• The correction accounts for your exact location and time zone

Nighttime Operation (6 PM - 6 AM)

• During nighttime hours, the system automatically reverses the arrow
• When "USE TAIL END" appears, follow the opposite end of the red arrow
• This accounts for the mathematical discontinuity in the watch method

Correction Feature

The correction system accounts for:

• Your exact longitude within your time zone
• Seasonal variations in the sun's position (declination)
• The Equation of Time (sun running fast or slow)
• Atmospheric refraction effects

Activate correction for precise navigation, especially near time zone boundaries.

Target Arrow Feature

Tap and drag on the watch face to set a target direction:

• A dark green arrow will appear showing your target direction
• The angle relative to true north is displayed in the lower right
• Target angle is saved in local storage
• This feature works alongside the existing compass functionality

Understanding the Display

• Digital Time: Current time in 24-hour format
• Correction Display: Shows how much to adjust the watch for true north
• Target Arrow: Dark green arrow showing your selected direction
• Target Angle: Angle of target arrow relative to true north
• Debug Info: Technical details for understanding the calculations
• USE TAIL END: Appears during nighttime hours (6 PM - 6 AM)

Technical Notes

This implementation uses sophisticated solar position algorithms that account for:

• Latitude and longitude effects
• Solar declination throughout the year
• Equation of Time corrections
• Hemisphere-specific calculations (automatically detected)
• The 6 PM/6 AM reversal to handle mathematical discontinuities

Time Zone Boundaries

When you're near time zone boundaries, the correction becomes especially important:

• The standard watch method assumes you're at the center of your time zone
• Near boundaries, this assumption can cause significant errors
• The correction feature adjusts for your exact longitude within the time zone
• This ensures accurate direction finding regardless of your position

Troubleshooting

• Arrow seems incorrect: Check if "USE TAIL END" is displayed (nighttime mode)
• Poor accuracy: Activate correction and ensure location access is enabled
• No location data: The watch uses default coordinates - allow location access for better accuracy
• Debug information: Use the debug panel to understand the calculations