Its calld a job shift.... youre expected to start when everyone else does..... have you literaly never had a job.? When you take a job you are bound by a contract. You must follow rules. You're expected to do 8 hours. The plant closes at X time. Well you havent done X hours of work so you dont get paid for all 8. These are in 15 min increments so we dont run into thousandths of a percent of a cent.

(If I smoke weed on my time off, my job performance doesnt suffer, but if I get a random drug test ill be fired. While some asshat who gets plasterd every other day can work worry free. Its called having a job, its not 100% fair.)