## 2010-10-18

### Diverting for a time

Have you ever pondered the logic behind our base 6 counting system for time? Or been confused by trying to figure out how many minutes or seconds are in two hours? four hours? six? If you have, you're not alone. To put it bluntly, our system of tracking time is messed up. It's confusing, weird to explain, even unnatural.

It's not really "metric" in the official International System of Units (SI) way - as I've been blogging for the last week - but there is at least one alternative to our current system of tracking the passage of time: decimal time.

The system of Decimal Time divides a day into 10 hours; where 0 is "midnight", making 5 "noon". It's an extremely simple concept to explain. Think of each moment as ticking away a percentage of that day. Noon is halfway through the cycle of the day, so 50% or 5:00.

Furthermore, each hour is divided into 100 minutes (00 through 99); again this gives us an extension on that percentage concept. The seconds of those minutes are the same. Fun fact, a "decimal second" is just about the resting heart rate of the average human being; meaning, you could almost keep time using your heart.

I, personally, use decimal time wherever I can, but - due the risk of confusing those around me - it tends to only be in specific instances where only my eyes are reading the display.

I'd like to demonstrate how natural decimal time is through some very simple exercises. Ready? (I guarantee you already know this as if you learned it as a child.)
If the sun rises at 2:50 and sets at 7:50, what percentage of the day was it transiting the sky?

How many minutes have passed between 5:00 and 7:00? How many seconds?

It's currently 9:23. How many minutes until it's 0:00?
Some of those were pretty tough, but I would guess that you figured them out with a little thought. Here are the answers: 50%; 200 minutes, 20000 seconds; 77 minutes.

Again, this is not related directly to the International System of Units nor would it be something which would be a part of the adoption of SI, but decimal time does demonstrate the strength and natural feel of a base 10 system.