No error raised on invalid dates

arrow/parser.py

@@ -165,6 +165,19 @@ def _generate_pattern_re(self, fmt):
 
         return tokens, re.compile(final_fmt_pattern, flags=re.IGNORECASE)
 
+    def check_incorrect_year_placement(self, string, fmt):
+        """
+        Determines wheather a year (YYYY) is incorrectly formatted.
+        """
+        if fmt == 'YYYY-MM-DD' or fmt == 'YYYY/MM/DD' or fmt == 'YYYY.MM.DD':
+            # Ensuring that the 3rd and 4th number of a date is a number
+            # instead of a '-', '/', or '.'
+            if not string[2].isdigit() or not string[3].isdigit():
+                return True
+            return False
+        else:
+            return False
+
     def parse(self, string, fmt):
 
         if isinstance(fmt, list):
@@ -280,7 +293,8 @@ def _parse_multiformat(self, string, formats):
                 _datetime = self.parse(string, fmt)
                 break
             except ParserError:
-                pass
+                if self.check_incorrect_year_placement(string, fmt):
+                    break
 
         if _datetime is None:
             raise ParserError('Could not match input to any of {0} on \'{1}\''.format(formats, string))

tests/parser_tests.py

@@ -375,6 +375,32 @@ def test_YYYY_MM_DD(self):
                 self.parser.parse_iso(separator.join(('2013', '02', '03'))),
                 datetime(2013, 2, 3)
             )
+
+    def test_incorrect_year_placement(self):
+        """
+        Tests when year is in the wrong slot.
+        """
+
+        with assertRaises(ParserError):
+            self.parser.parse_iso('02-2018-03')
+
+        with assertRaises(ParserError):
+            self.parser.parse_iso('02-03-2018')
+
+        with assertRaises(ParserError):
+            self.parser.parse_iso('02/2018/03')
+
+        with assertRaises(ParserError):
+            self.parser.parse_iso('02/03/2018')
+
+        with assertRaises(ParserError):
+            self.parser.parse_iso('02.2018.03')
+
+        with assertRaises(ParserError):
+            self.parser.parse_iso('02.03.2018')
+
+
+
 
     def test_YYYY_MM_DDTHH_mmZ(self):