I had a conversation with a CSR that told me Amex uses the approval date, not activation date. I asked her to verify my date for me and that was the one she gave me. For most people it wouldn't matter to much, maybe just a few days. But because of where I am it took 3 weeks for my card to get to me. Just thought I would put this out there, as always YMMV.
What's in my wallet: Cap1 Venture NFCU Sig Visa Delta Gold Amex BCE Citi Simplicity IHG World MC Amazon Visa CSP Starting Score: 5/2010 550-ish Current Score: 6/20/2013 TU 800 6/20/2013 EQ 770 6/20/2013 EX 775 Goal Score: 800 accross the board