"On-call" employees may be required by their employer to remain at their homes to receive telephone calls from customers when the company office is closed. If "on-call" employees have long periods of uninterrupted leisure during which they can engage in the normal activities of living, any reasonable agreement of the parties for determining the number of hours worked shall be accepted. The agreement shall take into account not only the actual time spent in answering the calls but also some allowance for the restriction on the employee's freedom to engage in personal activities resulting from the duty of answering the telephone.
N.J. Admin. Code § 12:56-5.7