Many workplaces offer overtime pay for employees who come in early and stay back late. When this OP worked at Kmart, they figured out that the machine they clocked in on would round to the closest quarter hour. So, they would always clock in and out 8 minutes early and late, so that they could get paid for 30 extra minutes instead of 16.
It may not sound like a lot but it added up to 2.5 hours of overtime a week and about 6.5 weeks of extra pay while they were there. If you’re thinking this sounds like a great idea, just stop. Thanks to digital clock-ins and more vigilant HR departments, this method just won’t work anymore.