The Clock / Sun Dial

[spathiphyllum]

How did the person who invented the sun dial know that 12 would be in the middle of day and night?

[Marshwarble]

The sundial was invented long before numbers. Even a stick can inform you whether it is early or late in the day.
Whether 12 is at night means nothing to people who only use sundials, this would only take effect when water clocks and candle clocks were invented.

[Buenchico]

The Egyptians invented the 24 hour system, with noon (when the sun reaches its highest point in the sky) at the centre of each day. Half-way through 24 hours, is 12 hours so (by definition) noon must occur at 12 o'clock.
http://www.abc.net.au/science/articles/2011/11/15/3364432.htm

[gingejbee]

....and when it's been cloudy for several days, you're stuffed. Then you invent the quartz-crystal clock....and then the caesium "atomic" clock.
No Sun needed!

[douglas9401]

It dozen really matter.

[Old_Geezer]

They simply set things up so that the midnight sun showed as 12 o'clock.

[Togo]

Haha the question made me laugh at least. Do bakers have a 26 hour clock? Is it double time on bank holidays, and time and a half on a really sunny day?

[Togo]

Spath..... just turn your clocks over by 90% and turn them back 3 hours.