On Tuesday 21 June 2005 00:47, Bill Potts wrote: > 24-hour time has been with us ever since the day was divided into 24 hours. > A more relevant question is why and when it was subdivided into two 12-hour > periods. I don't know the answer to that. Students of horology probably do > know it, though.
The day was divided into 12 hours of day and 12 hours of night. The length of these hours varied through the year, with night hours being longer than day hours in fall and winter, and the reverse in spring and summer. This system is still used for religious purposes and called "temporal hour" or in Hebrew "sha`ah zmanit". Next question is, when was the clock changed to start at midnight and noon, with all hours the same length, instead of at dusk and dawn, with different lengths of hours? phma -- GCS/M d- s-: a+ C++ UL++++$ P+ L+++ E- W+++ N+ o? K? w-- O? M- V- Y++ PGP++ t- 5? X? R- !tv b++ DI !D G e++ h+>---- r- y>+++
