Beyond that, Is it the time changing or time zone changing?
You don't have the cam time set to sync with a time source so it likely will drift over time. You should check the NTP box so that it can periodically sync its time with a time server. (Assuming that it has internet access. Which it shouldn't but that's another discussion. Can be done locally).
Also, if France uses a daylight savings adjustment you'd need to check the DST box and set that to appropriately offset the time.