Time Zone History

Honolulu time zone history

On standard time, clocks in Honolulu run 31 minutes ahead of local mean solar time. Local mean time, UTC−10:31:26, ended in 1896.

UTC−10

Standard time is UTC−10 (HST) all year under the current rules.

Covers: Hawaii · tz database name Pacific/Honolulu

Convert a time from Honolulu

UTC−10 every day since 1970

UTC−10:31:26, UTC−10:30: behind today’s standard timeUTC−10: today’s standard timeUTC−9:30: 30 minutes ahead of today’s standard timeUTC−10:31:26, UTC−10:30: behindtoday’s standard timeUTC−10: today’s standard timeUTC−9:30: 30 minutes ahead oftoday’s standard time

How to read this chart

Before 1970

18901910193019501970189019301970
JanFebMarAprMayJunJulAugSepOctNovDec1970198019902000201020202028JFMAMJJASOND1970198019902000201020202028

Standard time changes

DateChangeNew standard timeClock label
Before 1970
January 13, 1896Local mean time (UTC−10:31:26) replacedUTC−10:30HST
June 8, 1947Standard time forward 30 minutesUTC−10HST

Daylight saving periods

YearsClocks go forwardClocks go backShift and labels
1933April 30May 211 hour, HST to HDT
1942February 9not that year1 hour, HST to HWT
1945not that yearSeptember 301 hour

Also on UTC−10

Adak (United States), Tahiti (French Polynesia) and Cook Islands.

Clocks next door since 1970

  • Kiritimati (Kiribati) (2,162 km): usually 24 hours ahead; different on 9,130 days in 1970–1994.
  • Kanton Island (Kiribati) (3,074 km): usually 23 hours ahead; different on 9,130 days in 1970–1994.
  • Tokelau (3,710 km): usually 1 hour behind; different on 5,481 days in 2011–2026; 23 hours ahead today.
  • Adak (3,766 km): usually 1 hour ahead; different on 11,371 days in 1970–2026; same time today.
  • Tarawa (Kiribati) (3,855 km): always 22 hours ahead.

How it compares

The Honolulu zone has kept UTC−10 since 1947, with no clock changes since 1970.