I work at a chain discount store. A group of us have to arrive at 7:30 a.m. to restock the shelves; our assistant manager arrives with us to unlock the doors and make sure we show up. The store manager arrives at 8 a.m., when we all officially clock in. We all used to arrive at 8 a.m. and clock in immediately, but the manager decided that we needed more time before the store opens for stocking and inventory. Is it legal for the manager to keep us from clocking in until he arrives? This means we’re working for half an hour and not getting paid. I've complained to the manager, but he says he can do whatever he wants in his store.
This is not legal. In fact, it's a form of wage theft, for which you are entitled to damages.
The federal Fair Labor Standards Act (FLSA) and similar state laws set the wages and hours rules, including minimum wage, overtime, and so on. Your employer is violating the most basic wage rule of all, which is that employees have the right to be paid for the time they spend working.
There are some complicated wage and hour laws regarding the time immediately before and immediately after employees actually begin working. Recently, for example, the Supreme Court considered whether employees should be paid for the time they spend putting on safety gear or protective work clothing and taking it off again after their shifts. The Supreme Court is also considering whether employees should be paid for the time they spend in security screening (to detect theft) after their work shift is over but before they can leave the worksite.
Your situation presents no such grey areas, however. You are clearly performing a half hour of work and not being paid for it. The bottom line is that if you are working, you must be paid. The fact that you don't clock in until 30 minutes after you arrive doesn't mean you aren't working.
The law takes these kinds of violations very seriously. In your situation, your employer owes you -- and your coworkers who also arrive early -- half an hour's worth of pay for each day since this practice began. If this extra half hour puts you into overtime, your employer also owes the overtime premium (time and a half). You are likely also entitled to penalties and interest on the wages you didn't receive.
You should set up a meeting with an employment lawyer right away. If any of your coworkers want to join you, have them come along. The more employees who are affected, the bigger the claim against your employer, and the more likely your employer will be to take your claims seriously. A lawyer can help you come up with a strategy for getting what you are owed, starting most likely with writing a letter to the owner of the chain, explaining what's happening in your store and demanding that you and your coworkers be paid the wages than have been withheld from you.