diff --git a/hl7apy/base_datatypes.py b/hl7apy/base_datatypes.py
index 7bf4629..e1c4439 100644
--- a/hl7apy/base_datatypes.py
+++ b/hl7apy/base_datatypes.py
@@ -289,7 +289,7 @@ def __init__(self, value=None, out_format='%H%M%S.%f', offset='', microsec_preci
             raise InvalidDateOffset(offset)
         try:
             d = datetime.strptime(offset[1:], '%H%M')
-            if d.hour > 12:
+            if offset[0] == '+' and d.hour > 14 or offset[0] == '-' and d.hour > 12:
                 raise ValueError
         except ValueError:
             if offset:
diff --git a/hl7apy/factories.py b/hl7apy/factories.py
index 70a3fa1..b60524f 100644
--- a/hl7apy/factories.py
+++ b/hl7apy/factories.py
@@ -99,6 +99,7 @@ def datatype_factory(datatype, value, version=None, validation_level=None):
     except KeyError:
         raise InvalidDataType(datatype)
     except ValueError as e:
+        print(e)
         if Validator.is_strict(validation_level):
             raise e
         # TODO: Do we really want this? In that case the parent's datatype must be changed accordingly
diff --git a/hl7apy/utils.py b/hl7apy/utils.py
index 357a064..2ef0c0c 100644
--- a/hl7apy/utils.py
+++ b/hl7apy/utils.py
@@ -113,7 +113,7 @@ def get_datetime_info(value):
 
 
 def _split_offset(value):
-    offset = re.search('\d*((-|\+)(1[0-2]|0[0-9])([0-5][0-9]))$', value)
+    offset = re.search('\d*((\+(1[0-4]|0[0-9])|(-(1[0-2]|0[0-9])))([0-5][0-9]))$', value)
     if offset:
         offset = offset.groups()[0]
         return value.replace(offset, ''), offset
diff --git a/tests/test_datatypes.py b/tests/test_datatypes.py
index 94618d9..91e561d 100644
--- a/tests/test_datatypes.py
+++ b/tests/test_datatypes.py
@@ -102,17 +102,21 @@ def test_create_timestamp_by_factory(self):
         self.assertEqual(dtm.classname, 'TM')
         self.assertEqual(dtm.to_er7(), '120252.059+0200')
 
-        dtm = datatype_factory('TM', '120252.05+0200')
+        dtm = datatype_factory('TM', '120252.05-0200')
         self.assertEqual(dtm.classname, 'TM')
-        self.assertEqual(dtm.to_er7(), '120252.05+0200')
+        self.assertEqual(dtm.to_er7(), '120252.05-0200')
+
+        dtm = datatype_factory('TM', '120252.05+1400')
+        self.assertEqual(dtm.classname, 'TM')
+        self.assertEqual(dtm.to_er7(), '120252.05+1400')
 
         dtm = datatype_factory('TM', '120252.5+0200')
         self.assertEqual(dtm.classname, 'TM')
         self.assertEqual(dtm.to_er7(), '120252.5+0200')
 
-        dtm = datatype_factory('TM', '120252+0200')
+        dtm = datatype_factory('TM', '120252-1200')
         self.assertEqual(dtm.classname, 'TM')
-        self.assertEqual(dtm.to_er7(), '120252+0200')
+        self.assertEqual(dtm.to_er7(), '120252-1200')
 
     def test_create_nm_by_factory(self):
         nm = datatype_factory('NM', 100000)
@@ -156,6 +160,7 @@ def test_DT_wrong_default_format_strict(self):
 class TestTM(unittest.TestCase):
 
     def test_TM(self):
+
         time = datetime.strptime('01', '%H')
         time1 = datetime.strptime('0101', '%H%M')
         time2 = datetime.strptime('010111', '%H%M%S')
@@ -199,7 +204,7 @@ def test_TM_invalid_offset(self):
         self.assertRaises(InvalidDateOffset, TM, datetime.strptime('0101', '%H%M'), offset='+00:00')
         self.assertRaises(InvalidDateOffset, TM, datetime.strptime('0101', '%H%M'), offset='&0100')
         self.assertRaises(InvalidDateOffset, TM, datetime.strptime('0101', '%H%M'), offset='+100')
-        self.assertRaises(InvalidDateOffset, TM, datetime.strptime('0101', '%H%M'), offset='+1300')
+        self.assertRaises(InvalidDateOffset, TM, datetime.strptime('0101', '%H%M'), offset='+1500')
         self.assertRaises(InvalidDateOffset, TM, datetime.strptime('0101', '%H%M'), offset='-1300')
 
     def test_TM_custom_microsec_precision(self):