“ The rates of monthly basic pay and allowances for subsistence and quarters for members of the uniformed services provided for at Schedule 8-A are eflective on January 1, 1990. The rates of basic pay or salaries provided for at Schedules 1-A, 2, 3-A, 4, 5-A, 6-A, and 7-A are effective on the first day of the first applicable pay period beginning on or after January 1, 1990. ”