(a) All work in excess of the regularly scheduled eight (8) hour work day shall be considered overtime and computed on the basis of time and one-half (1 1/2) the regular hours or as otherwise provided.
(b) If an employee is requested to report back to work, not contiguous to the beginning or end of the regular shift, the employee shall be guaranteed a minimum of four (4) hours overtime. Contiguous time for purposes of this paragraph shall include periods within thirty (30) minutes of the regular shift.
(c) If the employee is requested to report to work more than two (2) but less than four (4) hours prior to but contiguous to the start of the shift, the employee shall be guaranteed four (4) hours overtime.