Time Zone History

Glace Bay time zone history

On standard time, clocks in Glace Bay run 12 seconds behind local mean solar time. Local mean time, UTC−3:59:48, ended in 1902.

UTC−4

Standard time is UTC−4 (ADT/AST); clocks go forward to UTC−3 on the second Sunday in March and back on the first Sunday in November.

Covers: Cape Breton, Nova Scotia · tz database name America/Glace_Bay

Convert a time from Glace Bay

Summer time in 55 of 57 years since 1970

UTC−4: today’s standard timeUTC−3:59:48: 12 seconds ahead of today’s standard timeUTC−3: 1 hour ahead of today’s standard timeUTC−4: today’s standard timeUTC−3:59:48: 12 seconds ahead oftoday’s standard timeUTC−3: 1 hour ahead of today’sstandard time

How to read this chart

Before 1970

18901910193019501970189019301970
JanFebMarAprMayJunJulAugSepOctNovDec1970198019902000201020202028JFMAMJJASOND1970198019902000201020202028

Standard time changes

DateChangeNew standard timeClock label
Before 1970
June 15, 1902Local mean time (UTC−3:59:48) replacedUTC−4AST

Daylight saving periods

YearsClocks go forwardClocks go backShift and labels
Before 1970
1918April 14October 271 hour, AST to ADT
1942February 9not that year1 hour, AST to AWT
1945not that yearSeptember 301 hour
1953April 26September 271 hour, AST to ADT
Since 1970
1972–1986last Sunday in April, 02:00last Sunday in October, 02:001 hour, AST to ADT
1987–2006first Sunday in April, 02:00last Sunday in October, 02:001 hour, AST to ADT
2007–2037second Sunday in March, 02:00first Sunday in November, 02:001 hour, AST to ADT

Clock changes in 2026, 2027 and 2028

The clocks go forward 1 hour (AST to ADT) on March 8, 2026, March 14, 2027 and March 12, 2028 at 02:00 and back 1 hour (ADT to AST) on November 1, 2026, November 7, 2027 and November 5, 2028 at 02:00, local time.

Also on UTC−4

Halifax (Canada), Moncton (Canada), Goose Bay (Canada), Bermuda, Puerto Rico, Dominican Republic, Pituffik (Thule) (Greenland), Martinique, Barbados and Venezuela (nearest first; 8 more on the list of offsets).

Clocks next door since 1970

  • Saint Pierre and Miquelon (292 km): usually 1 hour ahead; different on 5,060 days in 1970–2026.
  • Halifax (333 km): same time except 371 days in 1970 and 1971.
  • Moncton (372 km): same time except 555 days in 1970, 1971, 1973 and 1993–2006.
  • St. John’s (570 km): usually 30 minutes ahead; different on 587 days in 1970–2026.
  • Goose Bay (794 km): same time except 585 days in 1970, 1971 and 1987–2011.

How it compares

Standard time has stayed at UTC−4 since 1902.