Effective Date of Restatement on Transfer

I'm sure this has been beaten to death here. But say a plan transfers from service provider A to service provider B. What is best practice for the effective date of restatement to new document on the transfer to Provider B? Is it the day blackout lifts? Is it the day cash transfers from service provider A to service provider B?

We almost always restate to the beginning of the year.  I don't think there is anything special about blackout or cash transfer dates.  It's really about plan provisions and reliance on the opinion letter.  Of course if plan provisions are changing then that needs to be documented, maybe with different effective dates.