The clocks changed and now my older times look an hour off. Is this a bug?
This is due to daylight saving and relative timestamps.
Gyroscope uses the time of your phone, so if you travel or switch time zones it should update automatically or on your next app open. There isn’t a setting you need to switch. The app automatically picks up your phone’s local clock time.
One effect of this is that if you travel or the clocks change for daylight saving, older history will be shown relative to your current time, and the times may look different than when they were recorded.
Some people wrote in worried that it is a bug. Your data is never changed after it is logged, so this is just the actual time change in effect. What was previously 4pm may now be 5pm (or 3pm, depending on the direction).
Why do clocks change at all?
For most of history, every town kept its own time, set by the sun. Noon was when the sun was highest overhead, so two towns an hour’s ride apart could be several minutes apart.
History On November 18, 1883, the North American railroads switched to standard time zones. Many cities had two noons that day, once by the old local sun time and again by the new standard time. Congress made the zones law in 1918. What it means: Time zones started as a fix for train timetables. Today the zone your phone is in sets how your history is shown. |
Daylight saving time came later, as a wartime measure. Germany moved its clocks forward on April 30, 1916 to save energy, and Britain followed on May 21. A London builder named William Willett had campaigned for it since his 1907 pamphlet “The Waste of Daylight”, and died the year before it passed.
Today about 70 countries use daylight saving time in at least part of the country. Most of the world, including Japan, India and China, does not change its clocks. This year the UK and most of Europe set their clocks back on October 25, and the US and Canada on November 1.
What is UTC?
UTC, or Coordinated Universal Time, is the world’s reference clock, kept by atomic clocks in labs around the world. It never changes for summer, and it shows the same time everywhere on Earth at the same moment. That is why your data is stored in it.
The Earth’s spin is slightly uneven, so 27 leap seconds have been added to UTC since 1972 to keep it in step with the sun. In 2022 the world’s timekeepers voted to stop adding them by 2035.
Does the clock change affect my body?
Your body clock follows daylight, and the spring change, when an hour of sleep is lost, is the harder of the two.
Study Michigan hospitals saw about 25% more heart attacks on the Monday after the clocks moved forward in spring, and 21% fewer on the Tuesday after they moved back in autumn. The total for each week did not change. What it means: The lost hour of sleep seems to bring heart attacks forward by a day or two in people already at risk. The autumn change gives that hour back. |