For nurses who have been regularly working a shift described in Section 12 for thirty (30) or more days immediately preceding a paid holiday, comp time off, or the beginning of a vacation or a paid sick leave period, the applicable differential shall be included in the nurse’s holiday pay, vacation pay, paid sick leave, or paid comp time. The vacation, sick leave, holiday and comp time off pay of a nurse on a rotating shift shall include the differential such nurse would have received had they been working during such period.