Request for an Extra Day's Per Diem

An advance decision was requested as to whether an extra day's per diem may be paid to a Public Health Service officer who departed a day early on temporary duty to take advantage of an excursion air fare which resulted in a net savings to the Government. As the increased travel time did not interfer with the performance of the employee's duties because he traveled on a nonwork day and the cost of the extra per diem was more than offset by the savings to the Government through use of the excursion fare, the voucher submitted may be certified for payment if otherwise correct.