Ki Time Zone Specification

The Ki Time Zone (KiTZ) specification defines short, easily readable, and unique identifiers for common time zone names such as US/PST for US Pacific Standard Time and JP/JST for Japan Standard Time. Ki Time Zones are disambiguated with a two letter country code prefix. This is necessary for time zone names such as CST, which can mean China Standard Time, US Central Standard Time, Canadian Central Standard Time, or Australian Central Standard Time. Their Ki Time Zones are, respectively, CN/CST, US/CST, CA/CST, and AU/CST.

Q: Why not use Time Zone IDs from the IANA time zone database?

A: The IANA Time Zone DB is a comprehensive database, including historical time zones, that is useful for many purposes. That being said, it is cumbersome for many practical applications because the IDs are long, heavily redundant (multiple IDs for the same offsets in the same country), and aren't what people actually use when they speak or write. For example, everyone in Los Angeles, California (US) will tell you they are in the PST time zone, but the IANA timezone ID (formatted for ISO-8601 date/time) is [America/Los_Angeles]. Los Angeles's KiTZ, US/PST, is short, immediately recognizable and unambiguous. It applies to the entire US Pacific Standard Time Zone. During daylight savings time, it is US/PDT. Similarly, the IANA timezone ID for Buenos Aires is [America/Argentina/Buenos_Aires]. Argentina has one time zone but 13 IANA time zone IDs, all with the same UTC-3 offset. The KiTZ for Argentina is AR/ART. It applies to the entire country, is short, unambiguous, and easily recognizable as "Argentina Time" (ART is the common name for Argentina's time zone.)

Ki Time Zones are in beta, and are not yet comprehensive. Currently supported countries are Argentina, Australia, Brazil, Canada, Columbia, China, Czech Republic, Egypt, Ethiopia, France, Germany, Greece, India, Indonesia, Iran, Iraq, Ireland, Italy, Japan, Kenya, Mexico, Netherlands, New Zealand, Nigeria, Pakistan, Poland, Romania, Russia, Saudi Arabia, Singapore, South Africa, South Korea, Spain, Sweden, Switzerland, Turkey, Ukraine, United Kingdom, and United States.

The KiTZ spec does not capture historical time zones existing before January 1, 2020. Using UTC offsets is recommended for legacy time zones.

KiTZ	Country	UTC Offset
AR/ART	Argentina	-3
AU/ACST	Australia	+9:30
AU/ACDT	Australia	+10:30
AU/AEST	Australia	+10
AU/AEDT	Australia	+11
AU/AWST	Australia	+8
AU/NFT	Australia	+11
AU/NFDT	Australia	+12
BR/ACT	Brazil	-5
BR/AMT	Brazil	-4
BR/BRT	Brazil	-3
BR/FNT	Brazil	-2
CA/AST	Canada	-4
CA/ADT	Canada	-3
CA/CST	Canada	-6
CA/CDT	Canada	-5
CA/EST	Canada	-5
CA/EDT	Canada	-4
CA/MST	Canada	-7
CA/MDT	Canada	-6
CA/NST	Canada	-3:30
CA/NDT	Canada	-2:30
CA/PST	Canada	-8
CA/PDT	Canada	-7
CN/CST	China	+8
CO/COT	Columbia	-5
CZ/CET	Czech Republic	+1
CZ/CEST	Czech Republic	+2
EG/EET	Egypt	+2
ET/EAT	Ethiopia	+3
FR/CET	France	+1
FR/CEST	France	+2
DE/CET	Germany	+1
DE/CEST	Germany	+2
GR/EET	Greece	+2
GR/EEST	Greece	+3
IN/IST	India	+5:30
ID/WIB	Indonesia	+7
ID/WITA	Indonesia	+8
ID/WIT	Indonesia	+9
IR/IRST	Iran	+3:30
IR/IRDT	Iran	+4:30
IQ/AST	Iraq	+3
IE/IST	Ireland	+1
IT/CET	Italy	+1
IT/CEST	Italy	+2
JP/JST	Japan	+9
KE/EAT	Kenya	+3
MX/CST	Mexico	-6
MX/CDT	Mexico	-5
MX/EST	Mexico	-5
MX/MST	Mexico	-7
MX/MDT	Mexico	-6
MX/PST	Mexico	-8
MX/PDT	Mexico	-7
NL/CET	Netherlands	+1
NL/CEST	Netherlands	+2
NL/AST	Netherlands	-4
NZ/NZST	New Zealand	+12
NZ/NZDT	New Zealand	+13
NG/WAT	Nigeria	+1
PK/PST	Pakistan	+5
PL/CET	Poland	+1
PL/CEST	Poland	+2
RO/EET	Romania	+2
RO/EEST	Romania	+3
RU/KALT	Russia	+2
RU/MSK	Russia	+3
RU/SAMT	Russia	+4
RU/YEKT	Russia	+5
RU/OMST	Russia	+6
RU/KRAT	Russia	+7
RU/IRKT	Russia	+8
RU/YAKT	Russia	+9
RU/VLAT	Russia	+10
RU/MAGT	Russia	+11
RU/PETT	Russia	+12
SA/AST	Saudi Arabia	+3
SG/SST	Singapore	+8
ZA/SAST	South Africa	+2
KR/KST	South Korea	+9
ES/CET	Spain	+1
ES/CEST	Spain	+2
SE/CET	Sweden	+1
SE/CEST	Sweden	+2
CH/CET	Switzerland	+1
CH/CEST	Switzerland	+2
TR/FET	Turkey	+3
UA/EET	Ukraine	+2
UA/EEST	Ukraine	+3
UTC	United Kingdom	0
GB/DST	United Kingdom	+1
US/AST	United States	-4
US/AKST	United States	-9
US/AKDT	United States	-8
US/CHST	United States	+10
US/CST	United States	−6
US/CDT	United States	-5
US/EST	United States	-5
US/EDT	United States	-4
US/HST	United States	-10
US/MST	United States	-7
US/MDT	United States	-6
US/PST	United States	-8
US/PDT	United States	-7
US/SST	United States	-11