                     if let date = Date(rfc3339String: r) {
                         return Token.DateTime(date)
                     } else {
-                        throw TomlError.InvalidDateFormat(r)
+                        throw TomlError.InvalidDateFormat("####-##-##T##:##:##:##.###+/-##:## (\(r))")
                     }
             }, pop: true),
             // RFC 3339 w/o fractional seconds and time offset

                if let date = Date(rfc3339String: r, fractionalSeconds: false, localTime: true) {
                    return Token.DateTime(date)
                } else {
                    throw TomlError.InvalidDateFormat(r)
                }
            }, pop: true),
            // Date only

                if let date = Date(rfc3339String: r, localTime: true) {
                    return Token.DateTime(date)
                } else {
                    throw TomlError.InvalidDateFormat("####-##-##T##:##:##:##.### (\(r))")
                }
            }, pop: true),
            // Dates, RFC 3339 w/o fractional seconds and w/o time offset
