Time Zone History

Irkutsk time zone history

The Irkutsk zone has changed its standard time 4 times since 1970, the second-most of the 12 zones on UTC+8 standard time. The latest change of standard time came on October 26, 2014, from UTC+9 to UTC+8. On standard time, clocks at Irkutsk run 1 hour 3 minutes ahead of local mean solar time, the second-largest gap of the 9 zones on UTC+8 standard time whose clocks run ahead of the sun.

UTC+8

Standard time is UTC+8 all year under the current rules.

Covers: Irkutsk region and Buryatia · tz database name Asia/Irkutsk

Convert a time from Irkutsk

Summer time in 30 of 57 years since 1970

UTC+6:57:05, UTC+7: behind today’s standard timeUTC+8: today’s standard timeUTC+9: 1 hour ahead of today’s standard timeUTC+6:57:05, UTC+7: behind today’sstandard timeUTC+8: today’s standard timeUTC+9: 1 hour ahead of today’sstandard time

How to read this chart

Before 1970

187018901910193019501970187019101950
JanFebMarAprMayJunJulAugSepOctNovDec1970198019902000201020202028JFMAMJJASOND1970198019902000201020202028

Standard time changes

DateChangeNew standard timeClock label
Before 1970
January 1, 1880Local mean time (UTC+6:57:05) replacedUTC+6:57:05IMT
January 25, 1920Standard time forward 3 minutesUTC+7numeric only
June 21, 1930Standard time forward 1 hourUTC+8numeric only
Since 1970
March 31, 1991Summer offset kept as standard time; clocks did not moveUTC+7numeric only
January 19, 1992Standard time forward 1 hourUTC+8numeric only
March 27, 2011Standard time forward 1 hourUTC+9numeric only
October 26, 2014Standard time back 1 hourUTC+8numeric only

Daylight saving periods

Since 1970: the periods shared by 14 of 26 zones, listed on the Russia page.

Also on UTC+8

Ulaanbaatar (Mongolia), Shanghai (China), Taiwan, Macau, Hong Kong, Philippines, Malaysia, Singapore, Makassar (Indonesia) and Perth (Australia) (nearest first; 1 more on the list of offsets).

Clocks next door since 1970

  • Ulaanbaatar (Mongolia) (517 km): same time except 6,856 days in 1970–1977, 1981, 1982 and 1984–2016.
  • Chita (623 km): usually 1 hour ahead; different on 521 days in 1981–2011 and 2014–2016.
  • Krasnoyarsk (856 km): usually 1 hour behind; different on 3 days in 1981–2011 and 2014.
  • Hovd (Mongolia) (1,018 km): usually 1 hour behind; different on 6,855 days in 1970–1977 and 1981–2016.
  • Novokuznetsk (1,161 km): usually 1 hour behind; different on 1,675 days in 1981–2014.

How it compares

Daylight saving time was used in 30 years since 1970, last in 2010; under the current rules the clocks no longer change.

Irkutsk left local mean time (UTC+6:57:05) in 1880, tied for the earliest switch among the 26 zones in Russia.