Urgent question: xiaobaitu and others please help!!

My hu*****and filed 485 before retrogression and will become current in July.
I haven't filed my 485 and will file next month.
So I face the theoretical risk of my hu*****and got approved before I sent out my case, which would be very bad since it would displace me completely out of my hu*****and's EB process and I would have to wait for years to get my GC.
In order to minimize this risk, I want to get my case filed ASAP when possilbe.

My question is: what is the date that counts?
Do they look at the date on which I SEND my package or do they look at the date on which the RECEIVE my package?

Thank you so much!!