Summer Time and Time Zones
Daylight Saving Time (DST) extends beyond the astronomical summer
Civilian designations relative to GMT
There are 25 integer World Time Zones from -12 through 0 (GMT) to +12. Each one is 15° of Longitude as measured East and West from the Prime Meridian of the World at Greenwich, England.
There are both civilian designations which are typically three letter abbreviations (e.g. EST) for most time zones. In addition there are military designations. These use each letter of the alphabet (except 'i') and are known by their phonetic equivalent. E.G. Greenwich Mean Time (civilian) or z = Zulu (military and aviation).
- For details of Daylight saving (Summer) Time see here
Summer Time (or Daylight-Saving) Time Zones
There are many Daylight saving Time (DST) time zones, indexed by the zone hour value relative to both Greenwich Mean Time (GMT) and British Summer Time (BST).
BST - British Summer Time
ADT - Atlantic Daylight
EDT - Eastern Daylight.
CDT - Central Daylight
MDT - Mountain Daylight.
PDT - Pacific Daylight.
YDT - Yukon Daylight.
HDT - Hawaii Daylight.
MEST - Middle European Summer