Find the hour the whole world is awake — by real daylight.
How it works. Each ribbon is one city's sky across 24 hours, computed from its latitude and longitude for the chosen date — sunrise, the three twilights, golden hour and full day are all real astronomy, accurate to a couple of minutes, and run entirely in your browser. Every column is the same instant everywhere, so a vertical line reads across the whole world at once. Drag the gold meridian (or use ← →) to sweep time; hover a ribbon for a city's exact local time, sky phase and sunrise/sunset; Copy line-up drops every city's time at the selected moment into your clipboard. The panel finds the windows when everyone is awake — or in working hours, marked as a bright band across the ribbons. Rows start ordered west → east so daybreak cascades down the stack; drag the grip on the left to reorder them. Your places are remembered on this device.