Every working day of the year, checked against the real position of the sun where you live. Set your own hours and see which trips happen before sunrise or after sunset.
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Your whole year, day by day
Each column is one day, the vertical axis is the clock. Pale band: sun up. Dark band: night. Red bars are your dark trips, green bars your trips in daylight. Hover, tap or use the slider to inspect a day.
Sun upNightCivil twilightTrip in daylightTrip in the dark
What if you left earlier?
Share of your trips home that happen in the dark, for every possible departure time. Tap the curve to move your own departure.
Same hours, ten cities
Your own commute hours, moved to each city. Tap a city to switch to it.
Which months hurt
Share of trips in the dark, by month: mornings (left) and trips home (right).
How this is calculated, and sources
Sunrise and sunset use the solar equations from the NOAA Global Monitoring Laboratory Solar Calculator, which are based on Jean Meeus, Astronomical Algorithms. The page uses the same 90.833 degree zenith (0.833 degrees of refraction and solar disc). NOAA states results are accurate to about a minute between 72 degrees north and south. Source: gml.noaa.gov/grad/solcalc/calcdetails.html, code from main.js.
Civil twilight is the period when the centre of the sun is between the horizon and 6 degrees below it. Source: Wikipedia, Twilight.
City coordinates: Wikipedia page summaries for each city (example). Clock changes come from the time zone database built into your browser, so daylight saving jumps in the chart are the real ones for 2026.
A trip counts as dark when more than half of its minutes fall before sunrise or after sunset (or civil dusk, if you pick that). Weather, hills and buildings are ignored. Your location is used only in your browser.