Pre order / launch date

the create product template has two fields

Offer Start Date
“Once the product is launched on Amazon, customers can start placing orders on your product from this date”

Launch Date
“This is the date when customers will start viewing this product on Amazon”

I know one of them suppresses the asin’s product detail page until the set date.
And the other displays a preorder message and adjusts the customer delivery promise accordingly.
But I cannot remember which one is which.

Is the offer start date the one we should use if a product cannot be sent to a customer before that date?