Dating ru api Sa sex chatrooms
For example, Bristol is about 2.5 degrees west of Greenwich (East London), so when it is solar noon in Bristol, it is about 10 minutes past solar noon in London.
The use of time zones accumulates these differences into longer units, usually hours, so that nearby places can share a common standard for timekeeping.
Apparent and mean solar time can differ by up to around 15 minutes (as described by the equation of time) because of the elliptical shape of the Earth's orbit around the Sun (eccentricity) and the tilt of the Earth's axis (obliquity).
Mean solar time has days of equal length, and the difference between the two sums to zero after a year.
The zones were named Intercolonial, Eastern, Central, Mountain, and Pacific.
Within a year 85% of all cities with populations over 10,000, about 200 cities, were using standard time.
A notable exception was Detroit (which is about halfway between the meridians of eastern time and central time) which kept local time until 1900, then tried Central Standard Time, local mean time, and Eastern Standard Time before a May 1915 ordinance settled on EST and was ratified by popular vote in August 1916.