Attendance at lectures, meetings, training programs and similar activities need not be counted as working time if the following four criteria are met: (a) Attendance is outside of the employee's regular working hours; (b) Attendance is in fact voluntary; (c) The course, lecture, or meeting is not directly related to the employee's job; and (d) The employee does not perform any productive work during such attendance. 29 C.F.R. § 785.27