oleibman

I believe I may have found a way to duplicate your problem. I will keep you posted.

I hate to say it, but this looks like an Excel bug to me. I have read in the file where you originally reported a problem, and confirmed using mb_strlen...

I think I can confirm a bug in Excel. Run the following program: ```php $longstring1 = str_repeat('a', 32767); $longstring2 = str_repeat('b', 32767); echo mb_strlen($longstring1, 'UTF-8'), "\n"; echo mb_strlen($longstring2, 'UTF-8'), "\n";...

Closing this PR. The problem appears to be with Excel, not with PhpSpreadsheet, and the code in this PR won't fix it. I will leave the original issue open so...

No update in 4 months. Suggested solution seems to answer question. Closing.

When I open your spreadsheet (my setting is English US):  This is, of course, different than your setting because of the different regional settings, but it is entirely consistent...

How exactly does the user set the value you mentioned? On the spreadsheet? In code? If it's on the spreadsheet, Excel can treat the string as a date based on...

You are confusing "correct" with "matches my implementation". Excel does not always return the "correct" result for DATEVALUE. On my system, when I enter `=DATEVALUE("01/10/2021")` into an Excel cell, I...

Yes, you are wrong. The cell format is not an input to the DATEVALUE function. Only the string is an input, and it can be ambiguous.

I can confirm your reported behavior. It's easy to eliminate the error. I'm not sure how easy it is to get the behavior you want. At the moment, Title is...