Fairfax County Government Center - Department of Human Resources, 12000 Government Center Parkway, Suite 270. The first six months of employment are considered a probationary period.Offer letters or other written employment notification also must include information about the additional probationary requirement, as. (1) Fulltime employees who have not completed three continuous years of probationary service in Fairfax County Public Schools. Employees who have not completed a probationary period of twelve (12) months after original appointment. A new staff member is required to serve sixty working days during the probationary period before final certification as a status employee. Must enroll within 60 days of employment for guaranteed acceptance. Applying. How can I apply for jobs at WMATA? WMATA only accepts electronic applications through our online applicant tracking system.