Hijri Dates
If you use the English language version of Excel 2002, try entering the text below into a cell:
A1-1
You'll get the result shown below!
Furthermore, check the formula bar and you'll see that Excel interpreted your entry as a date -- March 25 of the current year. Take a look at the cell's number format, and you'll see that it's a custom format: B2d-mmm
This same weirdness occurs with other text strings that begin with A1 followed by a hyphen. This, I've been told, is a Hijri (Islamic) date. But I haven't been told why a Hijri date pops up in an English language version of Excel.
If your company uses part numbers with this format, that's a good reason to avoid upgrading to Excel 2002. (contributed by Bob Umlas)