If you leave at the same time every day on a road that runs east or west, the sun finds you on a schedule. It arrives on a date, stays a few weeks, and leaves on a date. Those dates are below for three cities; the app computes them for your actual route.
How the window works
Take a 7:30 departure heading east in Detroit. In July, sunrise is around 6:05 and by 7:30 the sun is already 15° up and to the north-east: over the visor, off to the side, no glare. Through August and September sunrise slides later, about a minute and a half a day, and its bearing swings toward due east. Some morning in early September the sun is 4° up and dead ahead as you pull out. It stays that way until sunrise has moved past the end of the drive, when you are once again in the dark for the whole trip. Spring runs the film backwards.
The rows below are a 25-minute drive on a straight road, sedan visor, counting any day with at least two minutes of sun in the windshield.
Detroit, MI
| Leave at | Sun in the windshield (2026) |
|---|---|
| 7:00 AM eastbound | Feb 19 – Mar 7 · Mar 27 – Sep 25 · Nov 1 – Nov 15 |
| 7:30 AM eastbound | Jan 24 – Mar 7 · Mar 10 – Oct 21 · Nov 1 – Dec 8 |
| 8:00 AM eastbound | Jan 3 – Nov 13 |
| 8:30 AM eastbound | Jan 29 – May 8 · Jul 22 – Oct 31 |
| 5:00 PM westbound | Jan 3 – Mar 7 · Sep 23 – Nov 30 |
| 5:30 PM westbound | Jan 20 – Apr 5 · Sep 4 – Oct 31 |
| 6:00 PM westbound | Feb 12 – May 4 · Aug 15 – Oct 31 |
Miami, FL
| Leave at | Sun in the windshield (2026) |
|---|---|
| 7:00 AM eastbound | Jan 1 – Mar 7 · Mar 22 – Oct 21 · Nov 1 – Dec 31 |
| 7:30 AM eastbound | Jan 1 – Dec 31 |
| 8:00 AM eastbound | Jan 5 – Nov 17 |
| 8:30 AM eastbound | Jan 28 – Feb 26 · Mar 8 – May 2 · Jul 16 – Oct 31 |
| 5:00 PM westbound | Jan 1 – Mar 7 · Sep 29 – Dec 31 |
| 5:30 PM westbound | Jan 1 – Apr 3 · Sep 2 – Nov 18 · Dec 11 – Dec 31 |
| 6:00 PM westbound | Jan 27 – Jun 25 · Jul 13 – Oct 31 |
Seattle, WA
| Leave at | Sun in the windshield (2026) |
|---|---|
| 7:00 AM eastbound | Feb 10 – Mar 7 · Mar 15 – Oct 11 · Nov 1 – Nov 20 |
| 7:30 AM eastbound | Jan 16 – Nov 23 |
| 8:00 AM eastbound | Jan 24 – May 14 · Jul 17 – Oct 31 |
| 8:30 AM eastbound | Feb 23 – Apr 21 · Aug 17 – Oct 31 |
| 5:00 PM westbound | Jan 26 – Apr 4 · Sep 4 – Oct 31 |
| 5:30 PM westbound | Feb 14 – Apr 27 · Aug 18 – Oct 31 |
| 6:00 PM westbound | Mar 6 – May 27 · Jul 26 – Oct 26 |
Dates are computed by the same code as the checker, for 2026, on the day's civil time in each city. A road that bends, a hill, or a taller vehicle shifts them by days, not months.
Reading the pattern
- Earlier departures have a short, sharp season near the equinox; later ones have a long one that drifts toward winter, because the later you leave, the further into the year sunrise has to travel to reach you.
- Miami's seasons are short and Seattle's are long. Sunrise moves fastest near the equinox at high latitude, so a northern commute spends more weeks with the sun at the wrong height.
- The evening season lags the morning one. Sunset moves earlier while sunrise moves later, so the westbound drive home meets the sun a few weeks after the eastbound drive in does.
To get your own dates, check your route once: the "coming weeks" strip on the result is this table for your road.