If you are an hourly employee, you are only paid for hours actually worked. An employer has the right to set the hours, schedule, etc., and may send employees home early if it choose; if it does, and they are hourly, they would only be paid for the hours they in fact worked. The exception would be if there is an employment contract guarantying a certain number of hours or daily pay, etc.; if there is a contract, its terms may be enforced.