Time zone abbreviations reference

PST, PDT, CET and CEST are useful shorthand, but they are not reliable scheduling keys. Use this table to map abbreviations to safer IANA timezone names.

Why abbreviations are risky

Some abbreviations change with daylight saving time, and some are reused by multiple countries. For future meetings, use an IANA zone like America/Los_Angeles, Europe/London, or Asia/Seoul.

Common timezone abbreviations

Abbr.	Name	Typical offset	Safer IANA zone	Notes
EST	Eastern Standard Time	UTC−5	`America/New_York`	Winter Eastern Time; use ET or IANA zone for dates.
EDT	Eastern Daylight Time	UTC−4	`America/New_York`	Daylight-saving Eastern Time.
CST	Central Standard Time	UTC−6	`America/Chicago`	Also used elsewhere; ambiguous without country.
CDT	Central Daylight Time	UTC−5	`America/Chicago`	US/Canada daylight Central Time.
MST	Mountain Standard Time	UTC−7	`America/Denver`	Some areas such as Arizona do not observe DST.
MDT	Mountain Daylight Time	UTC−6	`America/Denver`	Daylight Mountain Time.
PST	Pacific Standard Time	UTC−8	`America/Los_Angeles`	Winter Pacific Time.
PDT	Pacific Daylight Time	UTC−7	`America/Los_Angeles`	Daylight Pacific Time.
AKST	Alaska Standard Time	UTC−9	`America/Anchorage`	Alaska winter time.
AKDT	Alaska Daylight Time	UTC−8	`America/Anchorage`	Alaska daylight time.
HST	Hawaii Standard Time	UTC−10	`Pacific/Honolulu`	No DST in Hawaii.
GMT	Greenwich Mean Time	UTC+0	`Europe/London`	UK winter civil time and a global reference label.
BST	British Summer Time	UTC+1	`Europe/London`	UK daylight-saving time.
IST	Irish Standard Time	UTC+1	`Europe/Dublin`	Ambiguous: can also mean India Standard Time.
WET	Western European Time	UTC+0	`Europe/Lisbon`	Portugal winter time.
WEST	Western European Summer Time	UTC+1	`Europe/Lisbon`	Portugal summer time.
CET	Central European Time	UTC+1	`Europe/Paris`	Central Europe winter time.
CEST	Central European Summer Time	UTC+2	`Europe/Paris`	Central Europe summer time.
EET	Eastern European Time	UTC+2	`Europe/Helsinki`	Eastern Europe winter time.
EEST	Eastern European Summer Time	UTC+3	`Europe/Helsinki`	Eastern Europe summer time.
MSK	Moscow Time	UTC+3	`Europe/Moscow`	Russia; no seasonal DST in current rules.
TRT	Turkey Time	UTC+3	`Europe/Istanbul`	Turkey fixed time.
GST	Gulf Standard Time	UTC+4	`Asia/Dubai`	UAE and Oman; no DST.
IST	India Standard Time	UTC+5:30	`Asia/Kolkata`	Ambiguous with Irish/Israel labels; IANA zone is safer.
NPT	Nepal Time	UTC+5:45	`Asia/Kathmandu`	Quarter-hour offset.
CST	China Standard Time	UTC+8	`Asia/Shanghai`	Ambiguous with Central Standard Time.
HKT	Hong Kong Time	UTC+8	`Asia/Hong_Kong`	No current DST.
SGT	Singapore Time	UTC+8	`Asia/Singapore`	No DST.
JST	Japan Standard Time	UTC+9	`Asia/Tokyo`	No DST.
KST	Korea Standard Time	UTC+9	`Asia/Seoul`	No DST.
AEST	Australian Eastern Standard Time	UTC+10	`Australia/Sydney`	Standard offset; DST depends on state.
AEDT	Australian Eastern Daylight Time	UTC+11	`Australia/Sydney`	Sydney/Melbourne daylight time.
ACST	Australian Central Standard Time	UTC+9:30	`Australia/Adelaide`	Half-hour offset.
ACDT	Australian Central Daylight Time	UTC+10:30	`Australia/Adelaide`	Daylight central Australia.
AWST	Australian Western Standard Time	UTC+8	`Australia/Perth`	Western Australia; no current DST.
NZST	New Zealand Standard Time	UTC+12	`Pacific/Auckland`	New Zealand winter time.
NZDT	New Zealand Daylight Time	UTC+13	`Pacific/Auckland`	New Zealand daylight time.
SAST	South Africa Standard Time	UTC+2	`Africa/Johannesburg`	No current DST.
BRT	Brasília Time	UTC−3	`America/Sao_Paulo`	Brazil currently does not observe DST.
ART	Argentina Time	UTC−3	`America/Argentina/Buenos_Aires`	Argentina fixed time.

FAQ

Are timezone abbreviations unique?

No. CST, IST and other abbreviations can mean different zones in different countries.

Why should I use IANA timezone names?

IANA zones such as America/New_York include daylight-saving rules and historical changes.

Can UTC offsets replace time zones?

Only for a single instant. Future meetings need a real timezone because offsets can change with DST.