Seattle, WA
Representative 2027 solar times at the city center.Permanent DST scenario calculator
What would permanent daylight time feel like where you live?
See the tradeoff in clock time: darker winter mornings, later evening light, and no twice-yearly clock change.
Check your city
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7:30 AMStill dark?
5:30 PMStill light?
City comparison
Move the clock, not the sun.
Choose a city to compare three possible clock policies using representative 2027 solar times.
Month by month
When daylight lands on the clock
Each bar runs from estimated sunrise to sunset on the 15th of the month. The sunlit duration stays the same.
Current rules
Permanent daylight time
How it works
A transparent policy simulation
Solar position
Latitude, longitude, and date estimate sunrise and sunset at an unobstructed horizon.
Clock policy
The same solar event is labeled using current seasonal rules, permanent daylight time, or permanent standard time.
Everyday thresholds
The calculator counts mornings before sunrise at 7:30 AM and evenings with light after 5:30 PM.
Times are estimates and may differ by several minutes because of elevation, terrain, and atmospheric conditions. This tool is informational and does not predict whether the bill will pass.
Questions people are asking
Permanent daylight time FAQ
Has permanent daylight saving time become law?
No. The House passed H.R. 139 on July 14, 2026, but Senate action is still required before it could become law.
Would permanent daylight time create more daylight?
No. It would move winter sunrise and sunset one hour later on the clock in places that currently change clocks. The daylight duration is identical.
What happens in Arizona and Hawaii?
Most of Arizona and all of Hawaii currently avoid seasonal clock changes. This calculator assumes their opt-out remains unchanged; the Navajo Nation is a local exception not modeled here.
How accurate are the sunrise and sunset estimates?
They use a standard astronomical approximation for the city center and an unobstructed horizon. Local terrain and atmospheric conditions can shift the observed time by several minutes.
Primary sources
House passage of H.R. 139 ↗ U.S. DOT daylight saving rules ↗ State legislation tracker ↗ NOAA solar calculator ↗