Time zone codes and offsets

(Last modified: 30Oct2000)

This document (2908587) is provided subject to the disclaimer at the end of this document.


NetWare 4.x employs the use of timesync algorithms to maintain a consistent time for all servers in a given NDS tree. The timesync algorithms adjust a servers local time, initially read from the servers hardware clock, and then from the timesync time source, to obtain a common UTC (Universal Time Coordinate) or GMT (Greenwich Mean Time) time that NDS can use to keep track of operations and changes within an NDS tree. The adjustment is made by reading the timesync Time Zone string that is set up when installing a NetWare 4.x server and modified via SERVMAN.nlm.

The string has the format of XXX#YYY (for example MST7MDT) , where XXX is a meaningful representation of the local time zone (ie. MST = Mountain Standard Time), # is the offset or the number of hours that the local time differs from UTC (ie. 7 indicates that the local time is 7 hours less than UTC) , and YYY is a meaningful representation of the local daylight savings time (ie. MDT = Mountain Daylight Time). The XXX and YYY components of the string used for the time zone code are purely for the user's convience however using "non-standard" names will cause Java programs to use the incorrect time zone information.

The value used for XXX can be anything that is meaningful to the user. The important part is the # or the offset. If the location is east of the London, England (UTC) and west of the International Date Line the offset is given with a leading plus sign (+), indicating that the local time is actually ahead of UTC. The other half of the world's offset is given as an unsigned number, indicating that the local time is actually behind UTC. The value used for YYY is similar to XXX in that is can be anything that is meaningful to the user. However, the fact that there is a YYY is important. If a location has a daylight savings or summer time adjustment, a string must follow the # or offset. Once again the exact content of the string is simply for usablity. The total maximum length for the code, the offset and the alternate daylight savings time code is 80 characters.

As an example, the time zone string MST7MDT is composed of three distinct values MST, 7 and MDT.

     MST indicates Mountain Standard time. This could just as easily be XXX, AAA, MOU, etc.
     7 indicates that the local time is 7 hours behind UTC.
     MDT indicates that the location does utilize daylight savings time. Once again, this could just as easily be XXX, AAA, SAV, etc...

It is important to realize that the time sync code makes the adjustment by negating the number provided in the offset (offset = offset * -1) . For Mountain Standard Time, MST7MDT implies a -7 hours difference from UTC. For Australian Eastern Standard, AES-10 implies a +10 hour difference from UTC. Keep this in mind when viewing the following information. If the offset indicates +11 hours, this means that you want to adjust time to be 11 hours ahead of UTC. Therefore you must negate the value to end up with a positive adjustment. (Subtracting a negative is adding). Also realize that the time sync code currently cannot adjust for 1/2 hour increments.

The following is a list of areas, some common codes and their offsets.

Description Offset Codes

Australian Central Daylight +10:30 CSuT, ACDT, CDT
Australian Central Standard +9:30 ACST, CAST, CST
Australian Eastern Daylight +11 AEDT, ESuT
Australian Eastern Standard +10 AES, AEST, EAST, EST
Australian South Daylight +10:30 SADT
Australian South Standard +9:30 SAST
Australian Western Daylight +9 AWDT, WADT, WDT
Australian Western Standard +8 AWST, WAST, WST
Austria +1 WUT
Azores (obsolete) +2 AT
Baghdad +3 BT
Belgium, Mid-European +1 MET, MEWT
Bering Summer (1967-1983) 11 BST
Bering (until 1967) 11 BT
Brazil 3 BRA, BST
Brazil Summer 4 Horario_De_Verao
British Summer +1 BST
Canada, Atlantic Daylight 3 ADT, ASTU
Canada, Atlantic Standard 4 AST, ADT
Canada, Central Daylight 5 CDT
Canada, Central Standard 6 CST
Canada, Eastern Daylight 4 EDT
Canada, Eastern Standard 5 EST
Canada, Mountain Daylight 6 MDT
Canada, Mountain Standard 7 MST
Canada, Newfoundland Daylight 2:30 NDT
Canada, Newfoundland Standard 3:30 NST, NFT
Canada, Pacific Daylight 7 PDT
Canada, Pacific Standard 8 PST
Canada, Yukon Daylight 8 YDT
Canada, Yukon Standard 9 YST
Central Alaskan Standard (until 1967) 10 CAT
China Coast (obsolete) +8 CCT
China Daylight +9 CDT
China Standard +8 CST
Dansk Normal +1 DNT
Dansk Summer +2 DST
Europaeische, Mittel Sommerzeit +2 MESZ
Europaeische, Mittel Zeit +1 MEZ
European, Central +1 CET
European, Central Daylight +2 CETDST
European, Central Summer +2 CEST
European, Eastern +2 EET
European, Eastern Summer +3 EEST, EETDST
European, Middle Daylight +2 MEDST, MEST
European, Middle +1 MET, MEWT
European - Prague, Vienna +1 SET
European, Western Summer +1 WEST, WETDST
European, Western 0 WET
Fernando de Noronha Daylight 1 FDT
Fernando de Noronha Standard 2 FST
French Summer +2 FST
French Winter +1 FWT
Greenland, Standard (obsolete) 3 GST
Greenland, Eastern Daylight 1 WTZ
Greenland, Eastern Standard 2 VTZ
Greenland, Western Standard 3 UTZ
Greenland, Western Daylight 2 VTZ
Greenwich 0 GMT
Guam Standard +10 GST
Hawaiian Daylight (until 1947) 9:30 HDT
Heure Fancais d'Ete +2 HFE
Heure Fancais d'Hiver +1 HFH
Hong Kong +8 HKT
Indian Standard +5:30 IST
International Date line, East +12 IDLE
International Date line, West 12 IDLW
Iran Daylight +4:30 IDT
Iran Standard +3:30 IST
Iran +3:30 IT
Israeli Daylight +3 IDT
Israeli Standard +2 IST
Italy +1 ITA
Japanese Standard +9 JST
Java +7:30 JT
Korean Daylight +10 KDT
Korean Standard +9 KST
Malaysia +8 MAL
Melbourne, Australia +10 LIGT
Mexico 6 MEX
Moluccas (obsolete) +8:30 MT
Moscow Summer +3 MSD
Moscow W inter +2 MSK
New Zealand Daylight +13 NZDT
New Zealand Standard +12 NZT, NZST
Newfoundland Daylight 2:30 NDT
Newfoundland Standard 3:30 NST
Nome (until 1967) 11 NT
North Sumatran (obsolete) +8:30 NST
Norway +1 NOR, EMT
Samoa Standard 11 SST
Singapore Standard +8 SST
South Sumatran (obsolete) +7 SST
Spain +1 HOE
Swedish Summer +2 SST
Swedish +1 SWT
Thailand Standard +7 THA
Turkish Standard +3 TST, MAT
Universal 0 UT
Universal Time Coordinate 0 UTC
West Africa (obsolete) +1 WAT
United States, Alaska-Hawaii 9 AHDT
     Daylight (1967 to 1983)
United States, Alaska-Hawaii 10 AHST
     Standard (1967 to 1983)
United States, Alaska Daylight 8 AKDT
United States, Alaska Standard 9 AKST
United States, Atlantic Daylight 3 ADT
United States, Atlantic Standard 4 AST
United States, Central Daylight 5 CDT
United States, Central Standard 6 CST
United States, Eastern Daylight 4 EDT
United States, Eastern Standard 5 EST
United States, Hawaiian Standard 10 HST, HAST (10:20 until 1947)
United States, Hawaiian Daylight 9 HADT
United States, Mountain Daylight 6 MDT
United States, Mountain Standard 7 MST
United States, Pacific Daylight 7 PDT
United States, Pacific Standard 8 PST

UPDATE 000301:

Server-based JAVA applications, such as Zen for Servers, DO read and try to interpret the alpha strings of the Timezone field. Unfortunately the Java standard abbreviations differ from the ones in NetWare. For example NetWare uses EST for both US and Australian Eastern Standard Time, whereas Java uses AET for the Australian one. This means that all servers in the Eastern states of Australia ( New South Wales, Victoria, Tasmania, Queensland and the Australian Capital Territory ) that run time-dependent Java applications will need to modify their Timezone strings accordingly. In NetWare 5 at present this can only be done permanently by manually editing the autoexec.ncf file. The change can be made in Monitor - server parameters - time, but this is not written to the autoexec file and thus is lost after the next boot. Both should be changed.

Here is the table of Java timezones, as defined by Sun (we believe):

ID Raw Offset Name

MIT -11a Midway Islands Time
HST -10a Hawaii Standard Time
AST -9a Alaska Standard Time
PST -8a Pacific Standard Time
PNT -7a Phoenix Standard Time
MST -7a Mountain Standard Time
CST -6a Central Standard Time
EST -5a Eastern Standard Time
IET -5a Indiana Eastern Standard Time
PRT -4a Puerto Rico and US Virgin Islands Time
CNT -3.5a Canada Newfoundland Time
AGT -3a Argentina Standard Time
BET -3a Brazil Eastern Time
CAT -1a Central African Time
GMT 0a Greenwich Mean Time
ECT 1a European Central Time
EET 2a Eastern European Time
ART 2a (Arabic) Egypt Standard Time
EAT 3a Eastern African Time
MET 3.5a Middle East Time
NET 4a Near East Time
PLT 5a Pakistan Lahore Time
IST 5.5a India Standard Time
BST 6a Bangladesh Standard Time
VST 7a Vietnam Standard Time
CTT 8a China Taiwan Time
JST 9a Japan Standard Time
ACT 9.5a Australia Central Time
AET 10a Australia Eastern Time
SST 11a Solomon Standard Time
NST 12a New Zealand Standard Time


Document Title: Time zone codes and offsets
Document ID: 2908587
Creation Date: 08Jun1996
Modified Date: 30Oct2000
Revision: 4
Novell Product Class:Groupware


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