Lunar Holidays

"The Holidays" are considered to be at the end of the (solar) year, but around the beginning of the year there are a series of holidays which are based upon the phases of the moon.  These are determined according to various lunar calendars, which are sometimes called luni-solar calendars, because they are periodically adjusted by adding months to keep them somewhat synchronized with the solar seasons.

Decimated

The Economist online, of all places, posted an article on January 15 (55211) titled Decimated: What if Napoleon hadn’t abolished decimal time? The article talks about decimal time, the Egyptian calendar, decimal angle, etc.  It is not entirely accurate.  For instance, Napoleon did not abolish decimal time; it came and went before he came to power, although he did abolish the ten-day week.  And dual-face decimal clocks were not numerous in France in the 19th century, and certainly not elsewhere; almost all of them were made in the early 1790s.  It does mention Lagrange's suggestion for déci-jour and centi-jour, but he did not "try in vain" to get these as part of the metric system because France already had decimal time units.  As for the "compass", decimal angles called "grads" are actually common on calculators today, although I am not sure who uses them.  (The "gon" mentioned in the article is another word for the same thing.)  Then the article goes into hexadecimal time.  I'm not sure who uses that, either.  Unix time and Microsoft's filetime are mentioned, but not other systems, such as Microsoft Excel's decimal time and date.

By way of Calendar_Reform_with_Metric_and_Decimal_Time_Adoption.

MJD 55228.544
Tridi 13 Pluviôse an CCXVIII à 5^hd 51^md t.m.P.

Decimal Time Converter app

I've been posting a lot here about iPhone/IPod Touch/IPad apps, but I haven't mentioned the one app that actually has "decimal time" in it's name, Decimal Time Converter by CodeBurners (free).  That is because it is a different type of decimal time.

iPad apps

You have probably heard by now about the new Apple tablet that Steve Jobs announced here on Wednesday, the iPad.  Since it will run iPhone apps, that means that all the decimal time apps will work on the iPad the day it's released.  I have made a list on the right side of the page of all the apps I have posted about on this blog.

I don't know about apps on other devices, such as Android phones.  Does anyone else?

Metriclock iPhone app

Decimal time apps keep appearing.  Metriclock by Stotion was released on January 23 (55219) for $0.99.  It is not only a clock, but also a "metric stopwatch and metric timer".  The units have new names.  Decimal hours/decidays are called "alkas", decimal minutes/millidays are called "zimits" and decimal seconds are called "ozzis", I don't know why.  I have not tried it, but I see from the app store that it features a digital display with multicolored digits and a plain dark background.

The associated website is http://floint.com, which is in Flash, and therefore cannot be viewed on an iPhone.  Doh!  It's also difficult to view on my laptop, since it's a huge image which is larger than my screen, but I can see that it shows some pics of the app running on an iPhone.

MJD 55221.482

Wither Swatch .beats?

Apparently Swatch no longer sells .beat watches.  These were the only mass-produced watches with decimal time.  Fortunately, they are still available on eBay, where I bought one a few years ago.  I stopped wearing it when the band broke; I'm not much for wristwatches anyway, and I use my mobile for the time, like most people now.  Now the battery is dying, so the display is blinking and the light does not come on, but it still works, for the moment.

Decimal time notation

For some time I have looked for examples of how decimal time was used in France, so that I can represent it accurately in my scripts.  Most of them are written out in full, as in "five hours and fifty minutes decimal".   In both French and English of the period, it was customary to write a small "h", "m" and "s" after the hours, minutes and seconds, respectively, and even today it is common in French to put an "h" between the hour and minute, instead of a colon.  It therefore seemed likely to me that they would have written decimal times in a similar way, although they would have to distinguishable from standard times.

I have been trying to read Essai sur l'unification internationale de l'heure (Essay on the international unification of the hour) by Joseph Charles François de Rey-Pailhade, published in 1893.  Mostly it is about his proposal to use the centiday and the milliday, which he called cé and decicé, but he also writes about related subjects, including decimal time from a century previous, and includes examples such as:

3 heures 93 minutes (système décimal) 3^hd 93^md

It's a bit awkward to use double letters for each unit, but it seems likely to be correct, so I going to use this notation from now on.

Decadi 30 Nivôse an CCXVIII à 5^hd 77^md t.m.P.
MJD 55215.570