Answer:
End of the contract year.
Step-by-step explanation:
Calendar year deductibles (and refunds) operate on a regular calendar year basis, starting on January 1st and ending on December 31st. Generally refunds should be made during January and February of the next year.
If the policy works on a plan year basis, both the deductibles and the refunds will be based on the renewal date of the policy, and not the calendar year basis.