Holidays in French Guiana

Official national public holidays. Regional and religious observances may vary by area.

About Time in French Guiana

On July 1, 1911, Cayenne Turned Its Clock Back by 30 Minutes and 40 Seconds

Before standardized time, Cayenne used local mean time at UTC−03:29:20. The offset followed the local solar meridian rather than a round international time zone.

At the end of June 30, 1911, the clock did something unusual. After reaching 23:59:59, local time returned to 23:29:20. The final 30 minutes and 40 seconds of June 30 occurred twice. From that point, French Guiana used UTC−04:00.

The date comes from historical work incorporated into the IANA time-zone database. It forms part of the wider early twentieth-century shift in French territories away from local solar clocks and toward standardized offsets referenced to Greenwich.

French Guiana Stayed on UTC−04:00 for 56 Years, Then Skipped Midnight in 1967

The next civil-time reform came on October 1, 1967. This one moved in the opposite direction.

After 23:59:59 on September 30, clocks jumped directly to 01:00:00. The entire first hour of October 1 disappeared from local civil time, and French Guiana moved from UTC−04:00 to UTC−03:00.

That offset has not changed since. There has been no seasonal alternation and no later correction. A territory that made two substantial standard-time adjustments in the twentieth century has now spent almost six decades on the same clock.

Kourou's First Rocket Lifted Off Only Six Months After the Territory Changed Time Zone

The timing of the 1967 reform intersects neatly with the beginning of the space age in French Guiana. The move to UTC−03:00 took effect on October 1, 1967. On April 9, 1968, the first rocket launched from the new Guiana Space Centre at Kourou.

The vehicle was a Véronique sounding rocket. Historical records from the French space program place liftoff at 09:55 local time. Under the newly adopted offset, that was 12:55 UTC.

The flight was intended to test the new range's operational systems, including meteorology, tracking and flight safety. Precise time was built into those systems from the beginning: launch sequences, tracking observations and later orbital operations had to be correlated against a common reference rather than described only by the wall clock at Kourou.

A Modern Kourou Launch Is Routinely Published in Two Clocks

The Guiana Space Centre still exposes a distinction that ordinary local life rarely needs to think about. Launch announcements commonly give both Kourou local time and UTC.

For example, the Vega-C mission carrying Sentinel-3C and FLEX on September 14, 2026 lifted off at 22:21 in Kourou. The corresponding international mission time was 01:21 UTC on September 15. The same physical event therefore belongs to two different calendar dates depending on the clock being used.

That is not formatting trivia. Spacecraft operations involve tracking stations, control centers and orbital calculations distributed across countries. UTC provides the unambiguous reference; local French Guiana time tells people at the launch site when the event occurs on their own civil clock.

French Guiana Has Never Used Daylight Saving Time

France changes its clocks seasonally in Europe, but French Guiana does not follow that pattern. Its civil time remains UTC−03:00 throughout the year.

The IANA identifier is America/Cayenne. Its historical record contains the local mean time of UTC−03:29:20, the long UTC−04:00 period beginning in 1911 and the 1967 jump to UTC−03:00, but no daylight-saving rules.

That makes French Guiana an instructive case where political connection does not imply identical clock behavior. Metropolitan France and French Guiana share national institutions, yet their local-time rules are different because the territories use separate time-zone systems.

Frequently Asked Questions