I am not claiming to be clever by any means but the stupidity that is going on in Israel is indescribable [or maybe it is all corruption] Pfizer seems to know that after 12.01 mid-night [compare the Exodus from Egypt] their vaccine can’t be used anymore and -honestly- I can’t believe it- all our scientists in Israel are frozen from “fear”……. Has there ever been ANY DRUG where the expiration date was more than an extremely rough estimate !!?? [If there is such a thing….paracetamol etc will be still working 20 years after expiration likely]Many expired drugs from Europe are exported to Africa [for free I think] because the bureaucrats have to stick to the rules [and it does not cost them anything from their own pocket if they dispose of these drugs] Good luck [if you like drugs] for the Africans.
Now I am forced to come to “conspiracy” theory even if this is one of the last things I deal with. Many years ago I saw a very real documentary of how the producers of fridges, computers and many expensive gadgets working on electronics can be “set” at random for a time to make the gadget stop working by inbuilt chips [ of course at random, not to cause suspicion]

Therefore, your instrument may not have eternal life!

Jumping forward: the only super- clever solution to know when a vaccine would stop working is by “manipulating: it with a time set “super-mini chip” which will give instruction to stop working …..do I have to believe such a “conspiracy”?? I don’t wish to but it becomes near-real with the story of Pfizer vaccine and expiration time even if I am far from understanding chips which have been shown to be not just fantasy.
If you have another “good explanation” please write me this. Of course, probably the whole issue is just chasing after money for which Pfizer[and a few other companies] are well known. Get rid of all the “expired stuff….[maybe a hidden blessing]