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 blogs.office.com: "…today The power of AI wherever you go. Available on desktop and mobile devices. Connect with us on…"
Wikipedia's Microsoft Office[1] article says "On March 27, 2014, Microsoft launched Office for iPad, the first dedicated version of Office for tablet computers."
Fortune confirms Nadella "announced iPad versions of Microsoft Word, Excel, and PowerPoint, available today," published 27 March 2014, an exact match to the pin's stored date.
NBC News reports "Microsoft's new CEO Satya Nadella unveiled a version of Office[1] designed for the iPad at his first public event on Thursday in San Francisco," matching the pin's stored 27 March 2014 unveiling date.
Time reports the new Office[1] apps for iPad were "available starting at 2PM ET today," 27 March 2014, independently corroborating NBC's and Fortune's[3] same-day accounts and the pin's stored date.
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.