[dekhn]

I'm an ex-computation biologist who did most of his work in python but periodically had to interop with excel.

THe basic assumption I have is that when I input data into a system, it will not translate things, expecially according to ad-hoc rules from another domain, unless I explicitly ask it to do so.

It's not clear what data input sanitization would mean in this case; date support like this in Excel is deeply embedded in the product and nobody reads the documentation of Excel to learn how it works.