And to finish that last bit, if an argument of a call is not a `Date` or `Str`: * The compiler may reject the code at compile time for failing to type check; a

And to finish that last bit, if an argument of a call is not a `Date` or `Str`: * The compiler may reject the code at compile time for failing to type check; and, if it doesn't: * The compiler will reject the code at run time for failing to type check unless it's either a `Date`, or a `Str` that successfully coerces to a `Date`.