Here’s an article from the archives that explains the STAR program:
https://www.cleveland.com/business/2...ght_month.html
... STAR (Start The Airline Right) trophy ....
United Airlines, ...., created the STAR Award to encourage its hubs to put extra effort into getting the first flights of the day out on time, defined as within 15 minutes of their originally scheduled departures.
"An airplane that starts the day on time has a much higher likelihood of staying on schedule" for the rest of the day, even if it flies up to six more times, United said.
Delayed flights , on the other hand, can have a negative domino effect, keeping the next round of planes and flight crews from getting where they're supposed to go.