Final answer:
The two annual advancement cycles for military ranks E-4, E-5, and E-6 are Spring and Fall, with exams typically conducted in March and September respectively.
Step-by-step explanation:
The two annual advancement cycles for E-4, E-5, and E-6 ranks in the military are Spring and Fall. These cycles allow for the promotion of service members based on their eligibility. The advancement exams for these ranks are typically administered in March for the Spring cycle and in September for the Fall cycle, though this may vary by service branch and year. The advancement process is critical in maintaining the personnel readiness and hierarchy within the military structure and reflects a member's experience, job knowledge, and leadership abilities.