Is there a bug in Excel concerning dates?

Question

Please don\'t ask how I stumbled upon this but please try the following:

1. Type \"60\" into a cell in Excel.
2. Set the data type to a date format

Answer 1

It's not a bug - Excel accepts Feb 29th 1900 as a valid date. It's a historical issue.

Your 60 is being regarded as 'number of days since Jan 1 1900'.

More info:

http://polymathprogrammer.com/2009/10/26/the-leap-year-1900-bug-in-excel/