Time Zone: Nantes lies in the Eastern Time Zone (EST/EDT) and observes daylight saving time. The time zone in French: EST- Heure Normale de l'Est (HNE), EDT- Heure Avancée de l'Est (HAE).
When there's a risk of an area code running out of phone numbers, an 'Overlay Area Code' is created that has the same geographic boundaries as the existing area code. In this case, the 819 code has been Overlayed with one of the following codes: 468 or 873. New phone numbers in the Nantes area will be assigned with one of these codes: 819, 468 or 873. As a result, placing a call in the Nantes area will require 10-digit dialing (where you enter both the area code and then the phone number).