I’ve just uploaded a major update to my venerable (6 years-old!) JavaScript date extensions DP_DateExtensions. This was a near-complete rewrite of the component and like most hard (and some great) work it started with an error.
The question Alexey Vassiliev (who reported the bug) asked me is “how many days are there between March 1, 2012 and March 31, 2012?” Assuming Midnight for both dates the common sense answer is, of course, 30 days. My component however was returning 29 days… why?