Cymek said:

Would food be safe to eat a week past its use by date if kept in the fridge and unopened.
I forgot about two precooked meals and now they are past the use by date.
They are those precooked vacuum sealed ones

I compare to the original duration of shelf life. If they came with a month, I’d make sure the plastic hasn’t expanded, indicating gas forming microorganisms, then do the sniff test and eat if okay. If they only came with a few days I would chuck. So far has not resulted in my demise.