That number is 7.

If employees clocked in 8 minutes early, that would cross the threshold of a 15-minute, payable segment.

The home office in Charlotte NC (the station was in Iowa) felt that too much overtime was being paid, so they installed a time clock which stamped time cards. Overtime actually went UP, because employees had been UNDER reporting their hours. The genius station manager came up with a fix. He required people to clock in and out at the exact time they were scheduled to start and end work. And THEN go back to what they had been doing -- for no pay. That little management ruse got reported,, and shortly thereafter there was a new general manager.

When I was starting out in the grocery business. The only way to move up was to work some "Church Time" and any Department Manager (who were all hourly workers) was implicitly expected to put in a fair amount of off the clock work or they wouldn't be a Department Manager very long. Thankfully that ended for the most part in the 1980s when the company got nailed with a big EEOC complaint and settlement. They somehow miraculously came to the conclusion in the Ivory Tower that paying fines was much more expensive than doing the right thing from the start that included the big emphasis on working off the clock. Not the brightest crayons in the box, but they eventually learned.