Metropolitan France operates on Central European Time (CET) during winter months, which is 1 hour ahead of Coordinated Universal Time (UTC+1). During daylight saving time, observed from the last Sunday in March to the last Sunday in October, France switches to Central European Summer Time (CEST), which is UTC+2.
All of mainland France follows the same timezone. Major cities including Paris, Marseille, Lyon, Toulouse, Nice, Nantes, and Bordeaux all observe the same time. Note that French overseas territories operate on different timezones.
France technically has the most time zones of any country in the world—12 in total—when including its overseas territories. From French Polynesia (UTC-10) to Wallis and Futuna (UTC+12), France spans nearly the entire globe. However, mainland France uses only one timezone.