The sun does not rise in the east. It rises in the east twice a year, near March 20 and September 22, and drifts north or south of it the rest of the time. Where the roads run east-west, those are the weeks the morning drive looks straight into it.
Where the sun comes up, month by month
Detroit's mile roads run almost exactly east-west, so Detroit makes a clean example. This is the sunrise direction on the first of each month, and the minutes a due-east road has the sun dead in the windshield, for a sedan visor. Same math as the route checker.
| Date | Sunrise | Rises at | Eastbound glare | Sets at | Westbound glare |
|---|---|---|---|---|---|
| January 1 | 8:01 AM | 121° east-south-east | 8:01 AM–8:01 AM | 239° west-south-west | 5:10 PM–5:10 PM |
| February 1 | 7:45 AM | 112° east-south-east | 7:45 AM–7:48 AM | 248° west-south-west | 5:42 PM–5:46 PM |
| March 1 | 7:07 AM | 99° east | 7:07 AM–8:25 AM | 261° west | 5:03 PM–6:22 PM |
| April 1 | 7:14 AM | 83° east | 7:14 AM–9:01 AM | 277° west | 6:11 PM–7:58 PM |
| May 1 | 6:27 AM | 68° east-north-east | 6:27 AM–8:17 AM | 292° west-north-west | 6:41 PM–8:31 PM |
| June 1 | 5:58 AM | 59° east-north-east | 6:50 AM–7:54 AM | 302° west-north-west | 7:06 PM–8:09 PM |
| July 1 | 5:59 AM | 57° east-north-east | 7:01 AM–7:56 AM | 303° west-north-west | 7:15 PM–8:11 PM |
| August 1 | 6:24 AM | 65° east-north-east | 6:39 AM–8:16 AM | 295° west-north-west | 7:00 PM–8:37 PM |
| September 1 | 6:57 AM | 78° east-north-east | 6:57 AM–8:44 AM | 282° west-north-west | 6:19 PM–8:06 PM |
| October 1 | 7:29 AM | 94° east | 7:29 AM–9:05 AM | 266° west | 5:37 PM–7:13 PM |
| November 1 | 7:05 AM | 109° east-south-east | 7:05 AM–7:28 AM | 251° west-south-west | 5:03 PM–5:25 PM |
| December 1 | 7:41 AM | 119° east-south-east | 7:41 AM–7:50 AM | 241° west-south-west | 4:51 PM–5:00 PM |
Detroit, 2026. Compass bearings from north; 90° is due east, 270° due west. Glare windows use the sedan preset (sun under the visor below 15°, blocked above 25°) and a road pointing within 15° of the sun.
Why September and March
In June the sun comes up around 57°, well to the north-east. A driver heading due east has it 33° off to the left, outside the windshield's danger cone, and it climbs above the visor within the hour anyway. In December it comes up around 122°, to the south-east, 32° off to the right. Only near the equinoxes does the sunrise bearing pass through 90°, and for about six weeks either side it stays within the 35° cone where a low sun reaches the driver's eyes.
The second half of the story is the clock. Around the September equinox, sunrise in Detroit moves about 1.4 minutes later every day. A commute that leaves at 7:30 is in the dark in August, meets the sun at the end of the drive in early September, has it dead ahead by the middle of the month, and is clear again once sunrise slides past the time you park. The same slide runs backwards in March.
What this means for a fixed departure
Because the sun's bearing and the sunrise time both move on a schedule, a commute's glare season has a start date and an end date. Glare computes both for any route: type the drive, and the "coming weeks" strip shows the day it goes clear. For the eight most common departure times in fifty cities, the city pages list them today.
Westbound in the evening is the mirror image, one hour before sunset, and it arrives a few weeks after the morning one because sunset moves earlier while sunrise moves later.