The first entry is always the pin's source. Overall confidence is a weighted average of how firmly each reference supports the start and end times used above; a reference counts half as much for every 180 days older than the newest.
Wikipedia states that "Passard bought the restaurant from Senderens in 1986" and gives no month or day, so the pin takes that year's last day. The event dated here is the change of hands and name, not a first opening - the room had traded as L'Archestrate before it.
Something missing or wrong? Say it in your own words: a link that backs this pin up, a different start or end date and why, or a fact it lacks or gets wrong. The AI checks it against this pin's sources, searches for better ones, and adds any page that backs you up. The pin's own sources still count most.