S2 Member Pro Question

[Gayatriom]

Hey! My client wants to keep membership free until April.
He is using Google Checkout with S2 Member Pro.
However I see that it is not possible to set an end date for 'for trial subscriptions'.

He doesn't want to do a trial period.
So- is it possible to set the paid membership amount to zero until March 30th (don't set a payment amount) and then on April 1st manually change the fee for the paid level and thus charging 'paid' subscribers at once from April 1st for the entire month?

Thanks!