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São Tomé and Príncipe Changes Its Time Zone

The African country of São Tomé and Príncipe has changed its local time from Greenwich Mean Time (GMT) to West African Time (WAT) on January 1, 2018.

Illustration image

Beach in São Tomé and Príncipe.


1 Hour Ahead

At 01:00 (1:00 am) on January 1, 2018, clocks in São Tomé and Príncipe moved 1 hour ahead. The African island nation previously followed Greenwich Mean Time (GMT), which is the same time as Coordinated Universal Time (UTC). Following the change, it observes West African Time (WAT), which is 1 hour ahead of UTC.

The Portuguese-speaking country, which lies in the Gulf of Guinea, now observes the same local time as many central African countries, including Angola, Cameroon, and the Democratic Republic of the Congo.

Energy Savings

The government justified the switch, which will result in a delayed onset of dusk and a later sunset, as a means to save energy.

Many countries around the world change their clocks for Daylight Saving Time (DST) for parts of the year, also in an effort to conserve energy. However, seasonal clock changes are meaningless in the tropics, where day lengths hardly vary during the year. While clocks in São Tomé and Príncipe do not change on a yearly basis, the recent switch to WAT amounts to the introduction of permanent DST in the country.

Close to Solar Time

Both GMT and WAT are fairly close to the local solar time, with solar noon occurring about half an hour before 12:00 (12 noon) before the change and about half an hour after that time following the change.