A Civil Twilight

A Civil Twilight shows the four solar times that define usable light:

• First light — morning civil twilight begins
• Sunrise — morning twilight ends
• Sunset — evening twilight begins
• Last light — evening civil twilight ends

Glance at your watch or phone and know exactly how much light you have
left — out hunting, on the water, flying, photographing, or just planning
a dawn run.

WHY CIVIL TWILIGHT?
Civil twilight (sun within 6° below the horizon) is the standard that many
hunting regulations, FAA night-flight logging rules, and boating
navigation-light requirements are written around. It is also the
photographer's blue hour. This app gives you those boundaries precisely,
not approximately.

ON YOUR IPHONE
• Today's four times, front and center, on a twilight-sky backdrop
• Swipe up or down to step through days; jump anywhere with the
full-screen calendar
• Twilight alerts: get notified 5, 30, 60 minutes — or any custom
lead time — before first light or sunset
• A built-in field guide: what civil twilight is, the 6° rule, the
golden hour, and why these four times matter
• Choose your look: Twilight, Light, Dark, or Auto

ON YOUR APPLE WATCH
• All four times at a glance for your exact location
• Scroll through any day, ±180 days; tap the date for a calendar
• The period you are in right now is highlighted
• Watch-face complications: next light boundary, current solar window,
and first/last light

PRIVATE BY DESIGN
All calculations happen on your device using standard solar math. Your
location never leaves your watch or phone. No account, no ads, no
tracking, no network connection required.

Works anywhere on Earth, including high latitudes (where the sun may not
cross a boundary on a given day, the app shows it honestly).

From PresenceProof by JSC Biz LLC.