I have a start-up 401(k) plan excluding all prior service (effective 1/1/17). Eligibility is 21/1, calendar year plan. If an employee was hired 10/1/2016 will their eligibility computation period be 10/1/16 - 9/30/17 due to it being their first year of employment? Or since the plan excludes prior service is the eligibility comp period 1/1/17 - 12/31/17? Thanks!