bravo1six From Canada, joined Dec 2007, 391 posts, RR: 1 Reply 1, posted (2 years 1 month 6 days 1 hour ago) and read 2284 times:
There can be a difference between delivery date from the OEM to the airline and the date that the aircraft is registered. The only way to figure out the actual date that the airline took title to the aircraft is if you have a copy of the bill of sale. In the case of a leased aircraft, you'd need a copy of the lease (or, more likely, the lessee acceptance certificate).
But, in general, the registration date is close enough to the actual date.