For the eligibility requirements for entry into a retirement plan, if you have an eligibility period of only six months, does that mean that you have to use elapsed time for the initial eligibility period?

Are you thinking something along the lines of requiring so many hours during a 6 month period as opposed to the elapsed time method? like an eligibility year of service, just shorter?

I think you could (outside of a prototype) write something like that in, but you'd want to make sure that you had a fail safe that made everyone eligible no later than when they'd have earned two eligibility years of service (if you have no vesting), or one eligibility year of service (if you have vesting, or for the 401k feature of the plan if applicable).

no elapsed time required. you could, for instance (depending on the document) put an hours qualifier on it such as "600 hours in a 6 month period or 1000 hours in a 12 month period"