Time Zone History

Guinea-Bissau time zone history

On standard time, clocks at Bissau run 1 hour 2 minutes ahead of local mean solar time, the third-largest gap of the 13 zones in Africa whose clocks run ahead of the sun. Local mean time, UTC−1:02:20, ended in 1911.

UTC+0

Standard time is UTC+0 (GMT) all year under the current rules.

tz database name Africa/Bissau

Convert a time from Guinea-Bissau

Once a new standard time since 1970

UTC−1:02:20, UTC−1: behind today’s standard timeUTC+0: today’s standard timeUTC−1:02:20, UTC−1: behind today’sstandard timeUTC+0: today’s standard time

How to read this chart

Before 1970

190019201940196019001940
JanFebMarAprMayJunJulAugSepOctNovDec1970198019902000201020202028JFMAMJJASOND1970198019902000201020202028

Standard time changes

DateChangeNew standard timeClock label
Before 1970
December 31, 1911Local mean time (UTC−1:02:20) replacedUTC−1numeric only
Since 1970
January 1, 1975Standard time forward 1 hourUTC+0GMT

Also on UTC+0

Liberia, Côte d’Ivoire, Western Sahara, Canary Islands (Spain), Madeira (Portugal), Morocco, São Tomé and Príncipe, Lisbon (Portugal), United Kingdom and Faroe Islands (nearest first; 2 more on the list of offsets).

Clocks next door since 1970

  • Liberia (811 km): same time except 1,826 days in 1970–1975.
  • Cape Verde (923 km): usually 1 hour behind; different on 328 days in 1975.
  • Côte d’Ivoire (1,462 km): same time except 1,826 days in 1970–1975.
  • Western Sahara (1,719 km): same time except 4,908 days in 1975–1978 and 2008–2026.
  • Canary Islands (Spain) (1,807 km): usually 1 hour ahead; different on 9,452 days in 1975–2026; same time today.