Under the federal Portal-to-Portal Act, employers are only required to compensate workers for working time that's spent on activities related to their job. Generally, work that starts and ends at the work site is considered working time, unless mandated otherwise in an employment contract. That said, even non-working or idle periods while an employee is on duty at a work site are considered compensable working time. For example, factory workers waiting for machinery to be repaired are considered working during their period of inactivity and must be paid for that time. Employers, however, don't have to pay employees for idle periods of inactivity not related to an employee's job description. For example, employees who arrive to work early or stay late to talk with co-workers can't be compensated for that extra time. The Portal-to-Portal Act also eliminates from working time certain travel time and other similar activities performed prior or subsequent to the workday. For instance, travel from home before the regular workday and returning home at the end of the workday is considered a normal incident of employment and shouldn't be considered paid working time. On the other hand, if travel related to a job duty occurs during the workday or keeps an employee away from home overnight, it must be counted as hours worked. In general, as long as an employee is engaging in activities that benefit the employer, regardless of when they're performed, the employer has an obligation to pay the employee for his or her time.