As I was adding all of the different things that I wanted Date::Manip to parse, I parsed all of the ways that I could find to specify a date. But then I wanted to be able to parse "in 2 hours" as a date, which implied a date calculation of (NOW + 2 hours). So, after all of the standard date formats are tried (and fail), I pass the value to the delta parsing routine which will catch all of the expected delta formats (like 'in 2 hours'). The downside (if you can call it that) is that ANY number can be parsed as a number of seconds (and that's what has happened here).

It's unexpected... but it's also why, if you're parsing a date, you need to be somewhat familiar with the formats that Date::Manip knows about. It'll handle just about every date format imaginable, but you still have to be aware of the formats, otherwise an unexpected result can occur when you parse a format you didn't expect.