﻿ Decimal Time

# Current decimal time

 Regular time Decimal time Decimal hours

# Decimal time

Decimal time is a way of time keeping that aligns with our decimal system (based on factors of 10). Especially converting between time notation hh:mm:ss and decimal notation hh.mmss works very well.

Decimal time is built like this:

• 1 day has 10 hours
• 1 hour has 100 minutes
• 1 minute has 100 seconds

A day has 10*100*100 = 100'000 seconds. This comes close to the current day length of 86400 seconds while being decimal.
This causes a decimal second to be 15% faster than a regular second.
The french used this system for a short while.

# Layout

Layout of a day written as decimal time: D.HMMSS...

This layout is very easy to read and calculate with by merely shifting the decimal point:

• 1.37245835 decimal days
• 13.7245835 decimal hours
• 1372.45835 decimal minutes
• 137245.835 decimal seconds

All times above are the same decimal time

• No more fiddling with multiples and fractions of 60, 24 or 12.
• Converting between seconds, minutes, hours and days is only a shift of the decimal point position.
• Easy conversion between decimal notation and hh:mm:ss notation.
• Makes time a part of the decimal system.
• Computations involving times are much easier because they're simple decimal operations.
• Working with other decimal units becomes a lot nicer, for example m/s ↔ km/h conversion no longer needs the ugly 3.6 factor but 10 instead (1 m/s = 10 km/h).

• We have to buy new clocks. If your job involves selling clocks, this could be an advantage.
• Minutes and seconds are less divisible in base 10. For example ⅓ of an hour in the current system is simply 20 minutes. In decimal, it would be 33⅓ minutes.
• We probably need new unit names to prevent collision with current ones.
• Displaying decimal hours can be weird because it's always a single digit number, and minutes and seconds are not. Using two digits would leave the leftmost always at 0.
• Changes units based on time. For example the value for the speed of light (c). All values that depend on time would need to be calculated once for decimal time.

# Limits

• Decimal time is not applicable to days, since a year still has about 365 days.
• Dates cannot further be simplified as the factors of 365 are 5 and 73 (both prime), which are not "nice to use" in the metric system. You have to change the entire calendar to fix this.

# Metric time vs. Decimal time

Metric time defines a second, and then time-keeping is done using seconds only. SI prefixes are applied for large or small numbers.

This system does not cares for the actual time an entire day takes, but it also does not changes the current definition of a second.
Decimal time adjusts the length of a second to allow it to be used for the daily time-keeping tasks.

# Converter

Enter "classic" time or decimal time, then press the appropriate button. Please allow for up to 1 second of rounding error. The converter accepts values that are too large. If you want to know how much decimal time is 1000 classic seconds, you can just fill in 1000 into the box for the seconds. You don't need to convert to minutes and seconds manually.