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.
Happened as dated, per apple[2].com: "…. Video replay of today’s event will be available shortly. Video replay of today’s event will be ava…"
Apple's[1] iPhone 5s tech-specs page lists the "A7 chip with 64-bit architecture", M7 coprocessor, Touch ID, 4-inch 1136-by-640 display at 326 ppi, 112 grams, 8MP f/2.2 camera with True Tone flash, 120 fps slo-mo and battery ratings.
Wikipedia's[4] iPhone 5S article says it "introduced the Apple[1][2] A7 64-bit dual-core system-on-chip, the first 64-bit processor to be used on a smartphone", with the M7 and a sapphire Touch ID home button.
Wikipedia's[3] list of Apple[1][2] special events includes an entry for "Apple special event (September 10, 2013)" announcing the iPhone 5C and iPhone 5S under the tagline "This should brighten everyone's day," independently corroborating the pin's event and date.
9to5Mac reports Apple[1][2] sent invites for a "September 10th event, scheduled for 10 AM PST" (the pin's "This should brighten everyone's day" iPhone 5S event), matching the pin's stored 9 September 2013 date to within a day.
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.