Not just you. Perhaps no other software feature has caused more hours of lost productivity than Excel auto-formatting whatever to a date.

Edit: I wonder, does '1-1' count as a 'continuous string of letters and numbers'? I still don't want '1-1' to be converted to a date.

Yes, I had big issues with Excel converting a number range like "1-3" to "3rd January" when importing property data. Eventually switched to Libre Office which works much more intuitively.

One of the worst things is trying to work with hours as a value in excel it will convert them into time and dates and mess up in csv. Avoid.

Excel isn’t a csv editor I’d say. Better to use a text editor.

The other one is converting large or long strings of numbers into scientific notation…

And leading zeros, which is awesome when postal codes have them and shipping software uses csv imports. Somebody only has to open the file once, and it isn't immediately obvious unless people know to expect that.

I used to work with some data that would come across as CSV files but from non-technical people and required leading zeros on some fields. Trying to explain the difference between csv and excel ... or why you should not open those files in excel ... was difficult to say the least.

CSVs need an option to open as text. Or at least to tell people "hey, there butchered your data for ya" with an undo option. I got a ticket from IT dept (lol) that a CSV is the wrong format. It wasn't.

This article says the user will be notified if any data is automatically converted when opening a CSV. This should have been done a decade ago but I'm still glad to see it.

> When you select the When loading a .csv file or similar file, notify me of any automatic number conversions check box,

From what I can tell, these are all opt-in via settings. So it won't stop unaware users from accidentally messing up csvs

US data formats, REGARDLESS of any regional setting you might have for dates. So even if they were dates being auto-formatted, they were still doing it wrong.

Anyone done this? Open a .csv in excel to fix/edit a item, then save it without realizing that it autoformatted a bunch of columns. Now it doesn't work in the parent program anymore.

Excel isn't the only MS product with US date insanity. Outlook set up for AU region only supports date filtering in searches using US date formats, which is the icing on the turd sandwich of date searching as Outlook requires you to hand write in text search queries to search for before/after x date.