Time Zone
A geographical region in which one time is valid for all places. There are 24 time zones on Earth. They were established in 1884 and there is a difference of one hour between one time zone and the next one. In theory, the time zones are all 15 degrees of longitude in size, but in practice the division has been adapted to political borders around the world. In each time zone a standard local time is based around a particular degree of longitude. For example, Middle European Time (MET) is concurrent with the local time at 15 degrees East of longitude. In Germany, for example, Goerlitz is located at this degree of latitude.
When calculating a horoscope, the local time always has to be translated into Greenwich Mean Time at zero degrees of longitude, the prime meridian, which is also referred to as universal time.
The time zone is not the only significant factor when calculating a horoscope - it is also necessary to take into account whether or not Daylight saving time was in force at the time of the birth. The time in some countries may also deviate from the standard time in the zone in which they are located. For example, double summer time was in force during (and for some time after) the Second World War in Germany.
The Most Important Time Zones
Greenwich Mean Time is the standard zone and starting point for all other time zones. The deviation from Greenwich Time is given after the international abbreviation for each time zone:
GMT (0) Universal Time, also: Greenwich Mean Time, Greenwich Time
WET (0) Western European Time
WAT (-1) West African Time
AT (-1) Azores Time
AST (-4) Atlantic Standard Time
EST (-5) Eastern Standard Time
CST (-6) Central Standard Time
MST (-7) Mountain Standard Time
PST (-8) Pacific Standard Time
YST (-9) Yukon Standard Time
AHST (-10) Alaska-Hawaii Standard Time
CAT (-10) Central Alaska Time
HST (-10) Hawaii Standard Time
NT (-11) Nome Time
IDLW (-12) International Date Line West
CET (+1) Central European Time
MET (+1) Middle European Time
EET (+2) Eastern European Time
BT (+3) Baghdad Time
WAST (+7) West Australian Time
CCT (+8) China Coast Time
JST (+9) Japan Standard Time
EAST (+10) East Australia Time
GST (+10) Guam Standard Time
IDLE (+12) International Date Line East
NZST (+12) New Zealand Standard Time
