Different parts of Metropolitan France use either Central European Time (UTC+01:00) or Central European Summer Time (UTC+02:00). Metropolitan France Observes Daylight Saving time from the last Sunday of March to the last Sunday of October. 

The country uses 12 time zones, the highest in the world because it has several overseas territories. Before 1891, all the Metropolitan Cities of France had their times based on the local solar time. However, the times were unified in 1891 due to the railway timetable complications. 

The times were unified based on Paris solar time. In 1911 France adopted GMT+0 as the official time. In 1940 it switched the time in the northern part of France to GMT+2. However, GMT+1 remains the official time for Metropolitan France.

France’s time zones in its global territories range between UTC-10:00 in most parts of French Polynesia and UTC+12:00 in Wallis and Futuna. In specific, these time zones are:

UTC−10:00 — most of French Polynesia

UTC−09:30 — Marquesas Islands

UTC−09:00 — Gambier Islands

UTC−08:00 — Clipperton Island

UTC−04:00 (AST) — Guadeloupe, Martinique, Saint Barthelemy, Saint Martin

UTC−03:00 (PMST) — French Guiana, Saint Pierre and Miquelon

UTC+01:00 (CET) — Metropolitan France

UTC+03:00 — Mayotte

UTC+04:00 — Réunion

UTC+05:00 — Kerguelen Islands, Crozet Islands

UTC+11:00 — New Caledonia

UTC+12:00 — Wallis and Futuna

According to worldatlas