|There's more than one way to do things|
|( #3333=superdoc: print w/replies, xml )||Need Help??|
This is no longer in answer to you initial question, as dbp pointed out that Date::Calc does not provide an object interface, but I got curious as to what happens when you call a method on something that is not an object. Lessee...
Ah, that's right - you get the package name. I knew this ;).
So that answers your question: if no object has been created, calling a function with -> results in the function getting the package name as the first argument. This also explains the error in your script: Date::Calc::Add_Delta_Days gets 'Date::Calc' as the year, hence the usage message.
Update: See bart's post below for some more information on -> syntax.
In reply to Re^3: Perl module symbol import versus direct invocation