As an illustration of Ken's thorough explanation of harness expiry dates, I'll list here my TeamTech REWEBBED 6 pt. harness system w/arm restraints and expiry tags. Invoice date 3/16/20. New style tag valid thru 2022 ( no old style tag showing manufacture date). On the arm restraints the old style tag shows the manufacture date as 1st qtr, 2020 (no new style tag). Thus my harness system system expires end of 2025 using both methods of math. I also carry in the car the receipt as proof. See you all in May!