Decimal Time Clock & Calendar

The decimal system has become the international standard for many units of measurement (length, weight, volume, money), but it lags behind for time. Time and date have not yet been converted to the decimal system. Already at the time of the French Revolution, an attempt was made to apply the decimal system to the time (10 hours with 100 minutes and 100 seconds each) and the calendar (French Revolutionary Calendar). The new decimal time clock has 100 hours per day with 100 minutes and 100 seconds each. The new decimal time calendar has 10 days per week and 365 days per year with leap year.

Decimal Time Clock

UTC±0 (0° LON)

The slider applies to the clock and the calendar at the same time.

Use at your own risk.

Info about decimal time clock below.

Decimal Time Clock App Widget

Decimal Time Calendar

Current Date in the Decimaltime Calendar:

Current Date in the gregorian Calendar:

Current Decimal-Date as ISO 8601 / DIN 5008:

Current Decimal-Date in alternativ presentation:

Use at your own risk.

Info about decimal time calendar below.

Decimal Time Calendar App Widget

Decimal Time Clock Info

The Decimal Time Clock has
100 hours per day
100 minutes per hour
100 seconds per minute.

Time format = hour:minute (HH:MM)

Old 00:00 = New 00:00
Old 03:00 = New 12:50
Old 06:00 = New 25:00
Old 09:00 = New 37:50
Old 12:00 = New 50:00
Old 15:00 = New 62:50
Old 18:00 = New 75:00
Old 21:00 = New 87:50
Old 24 hours = New 100 hours

Old: 1 day = 24 hours = 1440 minutes = 86400 seconds
New: 1 day = 100 hours = 10.000 minutes = 1.000.000 seconds

Time format = hours:minutes:seconds (HH:MM:SS)

Old 1 hour (01:00:00) = 4,166 hours (04:16:66,66) New
Old 1 minute (00:01:00) = 6,944 minutes (00:06:94,44) New
Old 1 second (00:00:01) = 11,57 seconds (00:00:11,57) New

New 1 hour (01:00:00) = 14 minutes and 24 seconds (00:14:24) Old
New 1 minute (00:01:00) = 8,64 seconds (00:00:08,64) Old
New 1 second (00:00:01) = 0,0864 seconds (00:00:00,0864) Old

The analog dial of the decimal time clock is oriented according to the view from a location in the northern hemisphere towards the south: the sun rises in the east (left) and sets in the west (right). At 50 (noon), the sun crosses the celestial meridian (solar zenith). It is possible for watches in the southern hemisphere to mirror the dial vertically and reverse the direction of rotation of the hands.
Another comparison is that of a mountain climb. The ascent is started from the bottom and in the half the summit is reached - mountain party - half-time - snack - noon. From then on, it's going downhill.

00 = Midnight (start of day) / Full hour (hour start)
25 = Morning (quarter day) / Quarter hour
50 = Noon (Half day) / Half hour
75 = Evening (three quarters of a day) / Three quarters of an hour
00 = Midnight (end of day) / Full hour (end of hour)

Decimal Time Calendar Info

Current date in the decimal time calendar:

Date according to Gregorian calendar:

A possible representation of a decimal time date according to ISO 8601 / DIN 5008 is year-week-day.

From the last date format the day in the year results very simply, since the numbers of week and day result in the number of the day in the year.

The decimal time calendar begins with December 23, 1999 according to the Gregorian calendar.

The decimal time year begins every year directly after the winter solstice. It begins with the solar year and ends with the solar year, which gives a natural rhythm. On the other hand, the previous "months" (derived from "moon"), which are a remnant of times long past — when people literally lived by the moon — are not used in the decimal time calendar. The word "week" comes only from "change". Within which period a change is to take place can be determined arbitrarily.

In many professions, the 5-day work week is not a reality. A 7-day to 10-day work week is standard. The decimal time calendar has a similar number of weekly working days and weekend days compared to the Gregorian calendar.

Decimal time calendar: 109 weekend days. (without additional public holidays)
Gregorian calendar: 104 weekend days. (without additional public holidays)

Decimal time calendar: 256 weekly working days. (without additional public holidays)
Gregorian calendar: 261 weekly working days. (without additional public holidays)

The slightly increased number of weekend days is offset against the slightly lower number of weekly working days to the extent that more public holidays fall on the new weekend days with the decimal calendar.

Sundays have been placed on day 0 in this version of the decimal time calendar and are marked in red.
The weekday number of Sundays could alternatively be placed on a day 10. Then, however, the thing with the "week number and day number = day-in-year number" does not work any more.

The other weekend days are marked in orange. These could be called Friday and Saturday, which would make Friday live up to its name for the first time and make it a non-working day (free day).

Leap year day
The leap year day has been placed at the beginning of a decimal time year (0.0., if present then light blue).
The leap year day is set thus already directly at the beginning of a year and not somewhere in the calendar year. Strictly speaking, it is set in the previous year according to the Gregorian calendar, because the beginning of the year was set on 23.12. according to the Gregorian calendar.
A leap year day is a special day: the 0th day in the year. Alternatively, it could be added to the end of the previous year so that the first day of the year remains the 1st day of the year rather than the 0th day of the year. Whether the leap year day is placed on the 0th day in the leap year or on the 366th day of the previous year is purely a matter of taste. Both are possible. The leap year day disturbs less in the decimal time calendar, because it can be put on more flexibly.
The leap year day can also become a holiday.

In the Roman (lunar) calendar, the month of March was the first month of the year, making leap year day February 29 the last day of the year.

Christmas & New Year
The green days from 0.1. (1st day, Dec. 23, or in leap year Dec. 24) to 0.9. (9th day, Dec. 31 New Year's Eve, or in leap year Jan. 1 New Year) will be holidays. This is because the two Christmas holidays and New Year's Eve or New Year's Day fall in this decimal time week, and most people take vacations between them anyway. New Year's Day falls on 1.0. (10th day) and in a leap year on 0.9. (9th day) in the decimal time calendar.

It may also result in New Year's Eve and New Year's Day being placed on a different day in the decimal time calendar, such as the last and first day of a decimal time year, i.e., Dec. 23/24 in the Gregorian calendar.

The numbers with yellow background are the week numbers.
The numbers with green background are the holidays between Christmas and New Year's Eve/Day (in Gregorian calendar).
The zero days with red background are holidays (Sunday).
The eight and nine days with orange background are non-working weekend days (Friday and Saturday).
The numbers with light blue background are leap year days.
The numbers with bold black border indicate the current date.

Decimal Time Clock & Decimal Time Calendar Info

French Revolutionary Calendar

During the French Revolution, from September 22, 1792 to December 31, 1805, the so-called French Revolutionary Calendar (French: calendrier révolutionnaire français), designed in 1789, was the official calendar in France (including territories already conquered). The French Revolutionary Calendar, like the French Revolution, was rather chaotic. A new year was proclaimed after certain events and the years were not counted consecutively. Thus, there were Year I and Year II three times in alternating order. Year I of Liberty, Year II of Liberty, Year I of Equality, Year I of the Republic and Year II of the Republic. The beginning of the year was shifted several times over the years, from July to January and back to August, then September, January again, and finally September again.

In the French Revolutionary Calendar, a year had 12 months of 30 days, each with 3 decades of 10 days, plus an additional 5 days (6 days in leap years) as supplementary days, all of which were holidays. Jour de la Vertu — Celebration of Virtue. Jour du Génie — Celebration of Talent. Jour du Travail — Celebration of Labour. Jour de l'Opinion — Celebration of Convictions. Jour des Récompenses — Celebration of Honors. Jour de la Révolution — Celebration of the Revolution.

In historical books, the Latin-French month names as well as day names from the French Revolutionary Calendar are still mentioned and used. Autumn months: Vendémiaire, Brumaire, Frimaire. Winter months: Nivôse, Pluviôse, Ventôse. Spring months: Germinal, Floréal, Prairial. Summer months: Messidor, Thermidor, Fructidor. Decadal days 1-10: Primidi, Duodi, Tridi, Quartidi, Quintidi, Sextidi, Septidi, Octidi, Nonidi, Decadi.

At the beginning of Year III of the French Revolutionary Calendar, a decimal time clock time was to be officially introduced on September 22, 1794, by the Calendar Law of November 24, 1793. Already on August 1, 1793, with effect from July 1, 1794, the units of measurement meter, gram, liter as well as the monetary unit franc with decimal time system were officially introduced. For reasons that with the time change all clocks would have to be exchanged and that this was very expensive, the law was suspended indefinitely and thus did not enter into force until today.


In the dynasties of the cultures of China, decimal time has been used predominantly for the past 3000 years. One day (from midnight to midnight) was divided into 100 ke (ke 刻, kè). 1 Ke was divided into 100 Fen.

The clock goes after the moon

The 2 times 12 hours counting of a full day (24 hours day) has its cause in the 12 lunar months which form a lunar year. From these 12 lunar months the moon calendar consisted in antique time, which is still unofficially used up to the today's time. The division of a year into 12 lunar months was the reason to divide the day into 2 times 12 hours. In addition, this 12-hour system leaned on the sexagesimal system (calculation to the base 60) prevailing in Babylonia at that time. The emerging science in the Middle Ages did not change this much, as it divided a full day into 24 hours instead of 2 times 12 hours. Mechanical clocks have until today mostly a 12-hour dial. A wide spreading of the 24-hour-counting took place from 1850 with the railroad and its timetables.

Below seconds, the decimal system already exists from milliseconds.

Innovation for the economy

A decimal time calendar simplifies economic analyses and calculations, as they are easier to calculate with equal intervals, rather than with months of unequal length. Although a more evenly spaced calendar system based on calendar weeks already exists, it has not prevailed over handling with months. The general use of months belongs to a lunar calendar, which is only used in the field of esoteric. The Gregorian yearly calendar is aligned after the solar year.

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The decimal time association advocates the adoption of decimal time.
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