In regards to kosher supervision, what is the largest single gap that a mashgiach can leave the premise and still be considered practicing יוצא ונכנס?
We are told to check our mezuzos twice every seven years. What exactly does this mean? If the Chachamim/Poskim had meant once every 3.5 years, would they not have said this instead? With regard to ...
I heard it was twice in two years. Is that right? Where does that come from? If I have no reason to assume they became pasul do I still have to check them?