Decimal Time / Metric Time
In 1793, during the French Revolution, the French wanted to decimate decimalise the whole calendar and timekeeping. They somehow kept the 12 months per year, but each month had 30 days – 3 weeks with 10 days each. 360 days total, plus 5-6 buffer days at the end of each year, so the years still align to the seasons.
Each day was divided into 10 “hours”, 100 “minutes” per hour, and 100 “seconds” per minute.
(There’s also a nice web-based decimal clock here.)
Understandably, people didn’t like the new 10-day weeks with half a day off mid-week and one day off at the end of the week as this felt worse than a 7-day week with Sunday off. (Mathematically, there would be 36 full and 18 half = 56 days off in the decimal calendar vs. 52-53 in the traditional one.) Also, adapting to the new time proved difficult (old habits die hard) and was expensive as well (all clocks needed to be changed, old clocks wouldn’t sell anymore). Thus, this didn’t last long.
In terms of a globally equalised time, this was still bound to local time zones, so wouldn’t bring any advantages in that regard.
GMT / Universal Time / UTC
GMT was established in 1847, astronomers later started to use “astronomical GMT” – shifted 12 hours forwards, so all night observations are under the same calendar date. 1928, astronomers were fed up with mixups between “astronomical GMT” and the actual GMT and started referring to the actual GMT as “Universal Time” (UT), keeping “GMT” for their 12-hour-shifted astronomical version. (While non-astronomer people still used GMT for the actual, beginning-at-midnight variant.)
In 1956, slightly different times were officially introduced: one was corrected for polar motion of Earth, the other one also added corrections for seasonal variations. That’s when UT was renamed to UT0 with the new two versions being UT1 and UT2.
By 1960, a Coordinated time was developed – UTC. After some discrepancies about whether it should follow UT2 or UT1, in 1972 it was defined to follow UT1 within 0.9 seconds.
In terms of a universal time for around the world it’s not good for everyday use. Since it is based on Greenwich time, people on the opposite side of the globe would experience a date change during daylight/working hours. Terms like “yesterday” and “tomorrow” would need to be redefined. Also, there’s some kind of agreement on what social rituals happen at which local times. Things like the start of a workday, lunchtime, evening time, and night/sleep time can usually be assumed from the hour of the day. While time zones wouldn’t need to exist anymore, global UTC would still need you to make timezone-like calculations to figure out whether it’s socially acceptable to call your overseas buddy / schedule a meeting or not.
Unix Time
The Unix timestamp is stored in a 32-bit integer field. Early Unix systems used a 60 Hz internal system clock and based their timestamps on that, i.e. 60 increases per second, 3600 per minute, 216,000 per hour, 5,184,000 per day. But this proved inconvenient as that 32-bit field could only hold 828.5 days – about 2¼ years – before it would overflow. So, the reference called “epoch”, i.e. what time is considered “0”, had to be changed regularly.
In the mid-1970s, they changed it to be based on actual seconds and stored in a signed integer instead – so negative numbers/past dates are possible, too. They defined the “epoch” to be 1-Jan-1970 00:00:00 UTC. Using a 32-bit field, this gives a range from 13-Dec-1901 to 19-Jan-2038. Using larger fields and even fractions of a second are allowed, too.
This timestamp is the same for everyone around the globe. But for everyday use it’s too unwieldy and doesn’t have any relation to everyday life. However, it’s perfect for internal use in computer programs and has been adopted by basically every modern operating system.
Swatch Internet Time
A good 200 years after the French tried Decimal Time, in 1998, Swatch came up with the idea of a globally equal time so people spread throughout the world can coordinate their events on the Internet. They called it .beats, or: the Swatch Internet Time.
Similar to the French decimal time, this divided a day into 1000 units – the so-called .beats with each being 86.4 seconds long. Well-suited for everyday use. Fractions of .beats were also allowed in case you needed smaller increments, e.g. 0.1 .beats for roughly 9 seconds.
There was just one problem: .beats are based on Biel Mean Time (where Swatch has its HQ), UTC+1. And there's no consideration for how to handle the date. So, imagine an appointment scheduled for e.g. @250 on the 2nd of March. For someone from Berlin this would be 6am local time on the 2nd of March. So far, so good. However, the same @250 time observed in Los Angeles would mean 9pm on March 1st! Unless the participant from L.A. knows that they need to go by Switzerland's time zone's date, they'll miss the appointment by 24 hours. Similar to UTC, the point about social rituals applies here as well.
Universe Time
Ever since reading Glasshouse by Charles Stross I couldn't get its way of timekeeping out of my head. (I recently found out that this was inspired by/based on Vernor Vinge's A Deepness in the Sky novel.) Much like in Star Trek, for interstellar travel, clinging to a time system based on rotations of Earth around the Sun doesn't make much sense. Which is why in these novels people just kept the seconds but based everything else on factors of those. Together with metric prefixes you get some weird cross between the French decimal calendar and the Unix timestamp. But it works - at least for those novels.
| Time unit | Earth equivalent | Note |
|---|---|---|
| 1 second | 1 second | |
| 1 hectosecond (hs), 100 seconds | 1 minute 40 seconds | |
| 1 kilosecond (ks), 1,000 seconds | 16 minutes 40 seconds | |
| 10 kiloseconds, 10,000 seconds | 2 hours 46 minutes 40 seconds | historically, this could be called a myriasecond (mas) |
| 100 kiloseconds, 100,000 seconds | almost 28 hours, about "a day" | Stross calls it "a Diurn" in the novel |
| 1 Megasecond (Ms), 10 Diurns, 1,000,000 seconds | about 11½ days, can be considered something similar to "a week" | called "a Cycle" in the novel |
| 10 Megaseconds | about 116 days, a third of a year | historically, this could be called a Hebdosecond (Hs) |
| 30 Megaseconds, 30 Cycles | slightly over 347 days, about a year | called an "M-year"; this is the only outlier in Stross' novel that isn't a factor 10 and needs some calculation |
| 100 Megaseconds | about 3.2 years / 38 months | |
| 1 Gigasecond (Gs), 1,000 Ms | about 32 years |
And this is all based on the Unix epoch:
While the "full" timestamp is identical to the current Unix timestamp (see above), I think it makes a lot of sense to split it into its parts - similar to how most watches just show hours and minutes (and often seconds) and you have to press a button to see the current day or the full date.
If you don't need exact seconds - comparable to how classic clocks only show hours and minutes - you could even omit the last 2 digits as well:
This might be completely sufficient for everyday, sorry, everydiurn use. If you want to know where in the current Cycle you are or the current M-year, it could look like this:
The decimal indicating the Diurn in this Cycle (similar to a weekday) and the calculated M-year separately.
All in all, I love the concept. Timespans are just a simple addition. No need to mess around with this 60-seconds-per-minute, 60-minutes-per-hour, 24-hours-per-day, 30-or-31-sometimes-28-or-29-days-per-month nonsense. However, I have to admit that it is unsuitable for everyday(sic!) use. As long as we're bound to this rock spinning around the Sun, it makes absolutely no sense to base our days on 100 ks instead of the current 86.4 ks.
That Decimal Time/Decimal Calendar might actually be the better choice for us.
Likes
Reposts