You are only due pay for the time you actually worked in the first and last weeks of employment. If you are salaried non-exempt, you never have any legal expectation of being paid when you do not work. If you are salaried exempt, the law expressly makes a provision for the first and last weeks of employment - you are not due any pay for a portion of the pay cycle that occurred before your first day of work or after your last day of work.