I have an email for the 75,000/$2k offer that has an expiration of today 8/31. I called to upgrade and they said it was expired. In my experience when offers have an expiration date the offer period is always inclusive of the date of expiration. Have I always understood this wrong or is Amex a one-off for how they interpret expiration dates?

for reference, the exact wording is “Offer expires 8/31/2018” and the fine print states:
”If your request is not received by 8/31/2018, we will not process your request.”