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.
LACMA's own press release names the day: the David Geffen Galleries "open April 19". The museum is announcing its own building, so the date needs no inference.
Independent architectural coverage of the completed building, used for the dimensions and the way the galleries sit above the street.[1]
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.