diff --git a/sdk/metricsadvisor/azure-ai-metricsadvisor/azure/ai/metricsadvisor/_helpers.py b/sdk/metricsadvisor/azure-ai-metricsadvisor/azure/ai/metricsadvisor/_helpers.py
index a0f7fa279392..1fbd4479282a 100644
--- a/sdk/metricsadvisor/azure-ai-metricsadvisor/azure/ai/metricsadvisor/_helpers.py
+++ b/sdk/metricsadvisor/azure-ai-metricsadvisor/azure/ai/metricsadvisor/_helpers.py
@@ -192,7 +192,7 @@ def convert_datetime(date_time):
     # type: (Union[str, datetime.datetime]) -> datetime.datetime
     if isinstance(date_time, datetime.datetime):
         return date_time
-    if isinstance(date_time, str):
+    if isinstance(date_time, six.string_types):
         try:
             return datetime.datetime.strptime(date_time, "%Y-%m-%d")
         except ValueError:
@@ -200,4 +200,4 @@ def convert_datetime(date_time):
                 return datetime.datetime.strptime(date_time, "%Y-%m-%dT%H:%M:%SZ")
             except ValueError:
                 return datetime.datetime.strptime(date_time, "%Y-%m-%d %H:%M:%S")
-    raise ValueError("Bad datetime value")
+    raise TypeError("Bad datetime type")
diff --git a/sdk/metricsadvisor/azure-ai-metricsadvisor/tests/test_helper_methods.py b/sdk/metricsadvisor/azure-ai-metricsadvisor/tests/test_helper_methods.py
index 4935926f2354..37e879a3adcf 100644
--- a/sdk/metricsadvisor/azure-ai-metricsadvisor/tests/test_helper_methods.py
+++ b/sdk/metricsadvisor/azure-ai-metricsadvisor/tests/test_helper_methods.py
@@ -6,6 +6,7 @@
 # --------------------------------------------------------------------------
 
 import datetime
+import pytest
 from azure.ai.metricsadvisor._helpers import convert_datetime
 
 
@@ -25,3 +26,7 @@ def test_convert_datetime():
     input = datetime.datetime(2000, 1, 1)
     date_time = convert_datetime(input)
     assert date_time == datetime.datetime(2000, 1, 1)
+
+    with pytest.raises(TypeError):
+        input = tuple("2000-01-01 00:00:00", "2000-01-01 00:00:00")
+        convert_datetime(input)
\ No newline at end of file