That's probably good advice.
In the case in point the user was getting "bad date" responses if s/he tapped in "29-Feb" when calling up a Diary date. So it wasn't really a once every four years problem. Anyway, it's sorted out now:- user taps in "29-Feb" for a non-leap year ... program delivers "01-Mar" (but "29-Feb" if it
is a leap year).
By the way, the events I mentioned (about "losing PM's") took place 25 years ago. No wonder I feel so old these days. Anyone else remember KSAM* files? But even back then a decent programmer would (should) have trapped those dates when a closing date was entered at a value
less than (before) the opening date. Pretty basic stuff I would have thought.

Greetings to All on the Happy Occasion of Saint David's Day, by the way. The daffodils are out here (just about).

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Key Sequential Access Method