The time periods for a pay schedule vary from state to state. The amount of time you have before paying an employee for a set period of time also varies. For example if someone worked for you for seven days, in some states you have to pay him within seven days after the end of that period, or ten days from the day he stopped working for you, or in the case of Florida you can pay him whenever you want as long as you pay him, the state is not going to interfere.
Why these laws are different from state to state, no one knows. In Utah and Ohio, there is a different time limit for paying your employees than in Illinois or Idaho. The time limit for holding back salaries is also different. For some reason, if the employer is not able to pay you immediately for your labor then he has some time to pay you depending on how long you worked for him. The longer you worked for him, the longer he has to pay you. This doesnt necessarily mean you work for someone for six months and dont get paid for another six-months. You must get paid for work every fifteen days in most states. Only for contractual work that lasts a few days or couple of weeks are the employers able to hold back payments for a set period of time according to the state.
For example, if you worked for someone for a day, they have up to a day to pay you. If you worked for someone for a week, they have up to a week to pay you after which you can take the matter to court.
However, there is a federal guideline that states workers must be paid regularly, meaning you have to set pay periods. You cant have an inconsistent method of paying employees who work regularly for you as it is unlawful.