French numbers have ten digits starting with 0: landlines in the north-east start 03 and mobiles 06 or 07. The API drops the 0 and adds +33. A buyer in Kehl, a short walk across the Rhine, has a German +49 number and is billed and governed as a customer in Germany.
Strasbourg keeps Central European Time: 09:00 there is 13:30 IST in winter and 12:30 IST in summer. A booking question at 18:00 during the Christmas market reaches India at 22:30, and the 24-hour window keeps it answerable the next morning.
Article L34-5 of the French postal and electronic communications code requires prior consent before prospecting individuals by message; the CNIL's guidance does not name WhatsApp, so treat it like SMS. If your business is based in Strasbourg, talk to sales about whether InfiQ fits.