Our tests a few weeks ago were expired per the box, but extended by 6 months and the proctors seemed to know this, they did not comment on expiry.
It takes a bit of Google searching that I don't recall (try emed expiration date) and you can find a memo that lists by lot number the extended expiration date. I had some left over from our July trip that showed an 09/06/21 expiration date. I needed to do a home test and stores were out so I checked the web and found these had been extended to 12/06/21.
