This year, as every fourth year since 1904, the world will add an extra day on February 29, making 2024 a leap year. While that is generally accepted, debate is growing about whether we should keep adding the occasional leap second. It might seem like an arcane question of little relevance to most people, but with the Russian government firmly taking one side of the debate, things may not go smoothly. It’s not a likely cause for World War III, but we could still be hearing more about this soon, with several solutions under consideration.
One proposal, promoted by Dr Judah Levine of the Time and Frequency Division at the National Institute of Standards and Technology, is to move from frequent
Why The Leap Year?
The length of the day and year makes an argument against an intelligently designed universe. Instead of the time the Earth goes around the Sun being divisible exactly by the number of times it turns on its axis, we get 365.2422 days to a year. If we insisted on keeping every year to 365 days our calendar would get out of step with the seasons. People at high northern latitudes might miss snow on Christmas Day, but historically a bigger problem would have been confusion about when to plant crops.
That problem was largely solved through the introduction of a leap year every four years. When that proved insufficiently precise, the
Shorter Leaps in Time
There’s a mismatch in the naming of leaps. We don’t add a whole year on February 29, but we talk about leap years, not leap days. Yet when a second is added to the calendar, we call it a leap second, not the slightly extended period in which it belongs a leap hour.
That pedantry aside, the
Since 1972 every few years a second
Goodbye, leap second, hello, leap minute?
Now, however, there is dissension in the ranks. In 2022 the International Bureau of Weights and Measures (BIPM) voted to
This is where Levine comes in. As one of the select group of people paid to think about these things, he notes that most people’s lives won’t be affected if the Sun crosses the meridian a few seconds away from noon. After all, we live in broad time zones where clock time only matches the position of the Sun precisely along a single line of longitude.
“Having to deal with leap seconds drives me crazy,” Levine told the
Therefore, Levine suggests, we should let the seconds build up, the heavens getting ever so slightly behind clock time, until we’re behind enough to add a whole minute in. The few people who need their clocks to match the sky perfectly are those best positioned to make adjustments to official time.
There are a lot of advantages to this – people might even hold parties to celebrate the leap minute; leap seconds are too common to bother with.
Nevertheless, the conference failed to adopt Levine’s idea, in part because the leap second now has considerable inertia. An odd alliance is against change, including the Catholic Church and the British and Russian Governments. Their motives vary, but all favor the current system.
Attachment to tradition seems to motivate some, but it’s been reported that Russian satellites are designed around leap seconds. If so, a change may be more than a simple matter of reprogramming. There’s speculation abandoning the leap second could affect Russian military systems, but if so, don’t expect them to admit it.
That makes achieving change very difficult. It’s one thing to convince the Vatican that abandoning the leap second does not disconnect humanity from the cosmos. After all, it came around to Galileo eventually. It’s much harder to change the mind of a nuclear power who won’t even acknowledge their true reasons. Don’t expect riots over stolen time, but don’t book the leap minute party just yet.