As far as I understand: it's 90 days after the shipping date, so if they shipped on Dec 15 MPP would kick in on March 15 if you haven't ROI'd the value of BTC you used to pay for it. As to how they calculate the number of additional units they send to you, I have no idea, but I'll drop them an e-mail for you.
Hashfast clarified today that the MPP begins on 30 OCT.
HashFast Production UpdateMiner Protection ProgramFor those of you covered under the Miner Protection Program (
https://hashfast.com/miner-protection-program/), this delay will not affect the starting point from which benefits are calculated. For First Batch Baby Jets, the start date of the program will be retroactive to October 30th. We want to make sure a delayed ship date does not reduce the value of the program.
Ah, okay, sorry, I'm just getting home... I guess this is bad news for the people who bought Batch 2 with MPP.
I'll run this by my contact and see if she can confirm everyone is on the same page