On-call employees are employees who are not permanently employed by an employer. Such employees are called to work on a need basis. They may be employed for several months or for few days, depending upon the nature of work they have to perform. On-call employees are called on short notice, and often paid an hourly wage. They work on an uncertain work schedule.
The following is an example of a case law defining the term:
On-call employees are those employees who are required to remain at or within the confines of a designated post of duty for more than 40 hours a week for the purpose of rendering stand-by service, but who are not required to spend all of their tour of duty in the actual performance of work. A notable example of on-call employees are fire fighters who are on duty 24 hours and off duty 24 hours, or whose tour is a variation of this form of the two-platoon system. Fire chiefs, assistant fire chiefs, fire inspectors, and fire-fighting crews of crash trucks may be considered either as on-call employees or full-time employees, depending upon their established tour of duty and the requirements of their work assignment. On-call employees should be distinguished from those employees who have a regularly scheduled tour of duty which does not include time spent in stand-by-service but who may, on occasion, be required to remain on duty beyond their tour in order to render such service. [Conn v. United States, 107 Ct. Cl. 422, 438 (Ct. Cl. 1946)].