Advent Calendar 2026

One door a day, on your phone's date

Door 1 opens at midnight on 1 December, door 24 at midnight on 24 December. The date is the one on your own device, not ours, so a friend in Seoul opens each door about half a day before a friend in California.

Doors before today stay open: if you missed a few mornings, open them whenever you like. Doors after today stay shut until their date. If you set your clock back, doors you opened later stay hidden until their day comes again.

Behind every door there is one painted coast, one true line about it with its source, and the nearest lighthouse as the official light list writes it. The count of lit doors lives only in this browser.

Reading the plaque

Each door has a small brass plaque with the lighthouse's line from the light list, copied as published. Korean lights come from the Korea Hydrographic and Oceanographic Agency (KHOA) light list; the four Mediterranean lights come from OpenStreetMap's seamark tags.

Fl means flashing. A number in brackets is how many flashes come in a group. W, R, G and Y are white, red, green and yellow. The seconds are the period: the whole pattern repeats after that time. The metres are the height of the light above the sea, and M is the range in nautical miles. Fl(3) W 18s 87m 24M reads: three white flashes, every 18 seconds, 87 metres above the sea, seen 24 nautical miles off.

The lamp next to the plaque blinks that rhythm: half a second on for each flash, a second apart, then dark until the period ends. Light lists give the period and the grouping, not the exact flash length, so that part is simplified.

Paintings and credits

The 24 paintings are our own, made for Seawink, our coast game. Where a painting was made from reference photos, the photographers are named and linked inside the door. Twenty of the coasts are in Korea, four on the Mediterranean.

Two pairs of doors share a lighthouse (3 and 18, 22 and 23), because it is the nearest one to both beaches. The plaque says so.

Where each line comes from