Stop auto correction of number into a date

It's not non-trivial for me.  I'm a customer, giving feedback about Microsoft's product.  What people are asking for is a perfectly sensible request: options.  In this case, a perfectly reasonable (and intuitive) option to toggle off auto-dates. 

The fact that you, Ron, don't have an answer, and prefer the status-quo does not in any way lessen or negate the overwhelming support of choices.  The fact that this thread is still going strong 5 years later says as much about Microsoft's inability to fix its product or listen to its consumers, as it does about your inability to understand other perspectives.  There is a reason for the mass exodus from Edge and Windows 10, and I doubt the migration from Excel will lag far behind.

In this society, the manufacturer is free to make what they want -- and you are free to use it or not as you wish.  You can always buy something else -- but maybe not at the price you want.

What if I want the tool to work one way, and you want the tool to work another, and the manufacturer doesn't feel like accommodating both of us (or either of us).  Should he be forced to do so by fiat?  That is akin to slavery, and I would not want to live in such a society. 

To use your analogy, I happen to have several hammers with rubber heads (well, hard plastic).  They are useful in certain circumstances.  But I would not be using them to hammer nails with small heads into very dense material.  For that, I would purchase a different kind of hammer. It might be nice to have a two-headed hammer; or one with interchangeable heads, and I might even suggest that to the mfg, if it were important to me.  But if he didn't have one, I would either buy the right tool, or find a substitute if there were no one else making the exact kind of hammer I wanted.

To use a different analogy, I couldn't find a computer that had all the features that I wanted some years ago.  But I was free to educate myself, gather parts, and put something together that did satisfy my needs.

If you are unhappy with the way Excel works, there are other spreadsheet programs out there that you can purchase; or you can design and build your own tool that does exactly what you want.  There are many things I do with Excel that Excel itself doesn't support -- so I either work with Excel, or design (in my case in VBA, but others use different languages) a method to accomplish exactly what I want, using some features of Excel.

You can certainly complain in multiple forums about how Excel works.  If you get enough people riled up about it, it might put pressure on Microsoft to make some changes.  But in the meantime, you are without what you feel is an appropriate tool to accomplish your tasks.  Since Excel has been behaving in this manner for 20+ years, had you started back then, you would still be without an appropriate tool.  You might have had better luck designing and building your own and then both using it and even marketing it.

With regard to date translation in particular, I could certainly work with it being an option.  But many of the complaints in this thread have to do with data that comes from another source.  If you have a csv file, for example, that has a field of dates, and another field of values that look like dates but are not, you would still have to somehow tell Excel when to convert to a date, and when not to convert.  In the present version, we have the text import wizard.

For me it is trivial to just enter the non-dates as text; and to use the text import wizard when appropriate, and to write a VBA routine when needed for repetitive tasks.

But what if the manufacturer makes the appropriate tool ,but in the wrong fashion? Like a hammer with a rubber head, or with a 2 inch handle? And what if this is the only manufacturer around making said tool? Then it just becomes irresponsible.