The time at which employees shall be granted vacation shall be at the discretion of the appointing authority. Length of service and seniority of employees shall be given consideration in scheduling vacations and in giving preference as to vacation time.

18.1   Vacation Allowance Employees, excluding seasonal and extra-help, or as herein otherwise provided, shall be entitled to vacation with pay in accordance with the following schedule, based on a full time work schedule. Accruals listed are prorated for part time employees: During the first five (5) years of continuous service,