daylight model
A daylight atlas · 55°–79° north
Eight northern horizons. One solar year. Move through the calendar and watch daylight gather, disappear, and return.
Enter the atlas01 / Annual light
Each vertical mark is one day. Winter compresses the light; summer stretches it until sunset and sunrise become the same event.
Selected station
69.6492° N · 18.9553° E
18h 03m
The sun stays above the horizon for three quarters of the day.
02 / Field note
North of the Arctic Circle, daylight stops behaving like a daily promise. It becomes a season: arriving by degrees, lingering, then withdrawing.
Near the equinox, every station in this atlas receives almost the same twelve hours of light. Latitude appears quiet.
Move toward either solstice and the difference opens rapidly. At Longyearbyen, the sun remains absent for months, then refuses to set.
03 / Method
The atlas runs entirely in your browser. It asks for nothing, stores nothing, and calls no outside service.
Eight fixed coordinates trace an uneven ring around the northern hemisphere.
The day of year determines the sun’s angle relative to Earth’s equatorial plane.
Latitude and solar angle resolve into sunrise, sunset, and total daylight.
cos ω = sin(−0.833°) − sin φ · sin δ / cos φ · cos δ
Atmospheric refraction is approximated at −0.833°. Values are illustrative, not intended for navigation.