Normally we divide a day into 24 hours, each hour consisting of 60 minutes, each minute being 60 seconds -
making 86400 seconds in a day. This division dates back 4000 years to the Babylonians, who used a
system of counting based on multiples of 60 rather than the 10 that we use today.
We also frequently divide the 24 hours into two 12-hour periods - before and after noon - although nowadays
the 24-hour clock is also in common use.
However, there is no reason to stick with these subdivisions of the day simply because that's how it has always
been done. In the digital age, it might make sense to divide the day using the binary arithmetic which underlies
all our computers. Or perhaps we should use modern decimal subdivision of the day? How would these work?
Decimal time could divide the day into 10 decimal hours (d–hours) of 100 d–minutes, with 100 d–seconds per d–minute,
for example. A d–second would then be similar in length to a normal second with 100000 of them per day, making
1 d–second equal to 0.864 seconds, 1 d–minute equal to 1.44 minutes, and 1 d–hour equal to 2.4 hours.
Binary time might divide the day into 16 binary hours (b–hours) of 64 b–minutes, each having 64 b–seconds.
The day would then be 65536 b–seconds long, so 1 b–second would be 1.32 seconds, 1 b–minute 1.41 minutes,
and 1 b–hour 1.5 hours.
Displaying the time
Most modern clocks display the time of day either in digital form or using rotating hands on an analogue dial. Digital
clocks can usually be set to show the time in 12-hour or 24-hour mode, whereas analogue clocks always use the 12-hour
system, with the hour indicator rotating twice round the dial each day. The minute hand rotates once per hour, reading out
the number of minutes that have passed since the previous hour. The numbers on a clock face show the hours past midnight
or midday, and we have to learn that the 6, for example, also represents 30 minutes past the hour.
However, we may choose to display the time in some other way. We could represent the numerical values of the hours,
minutes and seconds (or d-hours or b-hours) in binary and display them using different symbols to represent the 1 or 0 values.
Or we could use a dial similar to a normal analogue clock, but marked off with different subdivisions, in which the hands
moved at rates appropriate to the time measuring system we were using.
On this site you can choose from the various methods described, to measure and display the current time in a range of different ways.
Using the Analog clock you can show the time using a 16-hour or 64-hour day, and you can
change the appearance of the clock face and hands if you wish. Clicking the clockface removes or restores the additional
information displayed on the screen.
The Binary clock displays the time in binary, with various graphical options
available for displaying the '1's and '0's of the binary coded time. The time itself can be measured in 16-hour, 64-hour
or 24-hour days. Clicking on the clock hides or restores the extra on-screen information.
The Digital clock shows the time using standard 7-segment LED displays as found
on many digital clocks. However the time is displayed using binary or hexadecimal digits, and the day may be divided
into 24, 2*12, 16, 64, 20 or 10 hours. Again, clicking the clock hides or restores the extra on-screen information.