In October 2026, the International Bureau of Weights and Measures decided to abolish leap seconds, which were additional seconds added at the end of June or December This change will allow UTC to gradually drift from mean solar time, potentially requiring a leap hour in thousands of years. The final leap second occurred on December 31, 2016.
The article examines the discrepancies between local time and solar time in Europe, noting that many EU countries, despite diverse longitudes, share the same time zone. It discusses types of time, the historical shifts in timekeeping, the debates on restoring natural time as civil time
At 2 AM local time on Sunday 25 October, the UK like most of Europe will put it clocks back by one hour as Daylight Saving Time (DST) ends. Most of the USA will follow a week later. In this post give an overview of DST, its pros and cons, why this practice is falling into disuse.
The standard unit of time in the SI system is the second, historically defined as 1/86400th of a mean solar day. The modern definitions since 1967 is based upon a caesium atom transition. The Earth's rotation is gradually slowing down meaning that in thousands of years' time the second may need to be redefined to bring it back in line with the mean solar day.
The post explains that a year is defined by Earth's orbital motion around the Sun, encompassing three types: the sidereal year (365.256 days), the tropical year (approximately 365.242 days), and the anomalistic year (365.259 days). It discusses their lengths, differences, and the implications for calendars, notably the transition from the Julian to the Gregorian calendar to align with seasonal changes.
