[Night Differential and Sunday Premium Pay Entitlement]

An employees union appealed a Claims Group settlement which disallowed the claim of 11 Internal Revenue Service (IRS) employees for night differential and Sunday pay. IRS concluded that the employees were not entitled to differential and premium pay for night and Sunday work, because such work was not included in their regular tours of duty. The union argued that: (1) the employees were entitled to their base pay plus a 10-percent differential for any regularly scheduled work performed between 6 p.m. and 6 a.m.; and (2) the employees were entitled to their base pay plus 25 percent for work performed during any part of a regularly scheduled 8-hour period of service which fell on Sunday. GAO found that: (1) differential may not be paid to employees who worked occasional overtime at night during a regularly scheduled tour of duty on or after February 28, 1983, when a revision to the applicable regulations went into effect; (2) night differential may be paid to employees who worked overtime at night during a regularly scheduled tour of duty, not necessarily their own scheduled tour of duty, prior to February 28, 1983; and (3) employees who performed Sunday work in addition to their basic 40-hour week and who were paid for the additional hours are not entitled to premium pay, since such pay is authorized only for nonovertime hours. Accordingly, night differential for work performed prior to February 28, 1983, but not premium pay for Sunday work, may be paid to the employees.