Date object expected
You attempted to invoke the Date.prototype.toString or Date.prototype.valueOf method on an object of a type other than Date. The object of this type of invocation must be of type Date. For example:
var o = new Object;
o.f = Date.prototype.toString;
o.f();
To correct this error
- Only invoke the Date.prototype.toString or Date.prototype.valueOf methods on objects of type Date.
See Also
Reference
Date Object (JScript 5.6)
getDate Method (JScript 5.6)