I think that 'no way to know' was a quote from a post of mine.
I was referring to whether the copying was done at the same time as each event was entered into the parish register or as a job lot just before the copy had to be submitted each year.
Whichever method was used, of necessity, the declaration would have been made, signed and dated 'after' the last event took place.
If the entries into each register, Parish and BT, were not made at the same time then the date of the declaration would be the same by which time the opening entry could be up to a year old.
Boo