This one has come up several times lately. Hence the need for a Q&A.
Or to put it another way. Given the copy takes “some time”, is the new database transactionally consistent with the original database at the point where the copy was started or at the point where the copy completed?
A new database created from the copy process is transactionally consistent with the source database at the point in time when the copy completes. This means that the snapshot time is the end time of the copy, not the start time of the copy.