diff --git a/tableauserverclient/models/interval_item.py b/tableauserverclient/models/interval_item.py
index 3ee1fee08..444674e19 100644
--- a/tableauserverclient/models/interval_item.py
+++ b/tableauserverclient/models/interval_item.py
@@ -246,21 +246,34 @@ def interval(self):
 
     @interval.setter
     def interval(self, interval_values):
-        # This is weird because the value could be a str or an int
-        # The only valid str is 'LastDay' so we check that first. If that's not it
-        # try to convert it to an int, if that fails because it's an incorrect string
-        # like 'badstring' we catch and re-raise. Otherwise we convert to int and check
-        # that it's in range 1-31
+        # Valid monthly intervals strings can contain any of the following
+        #   day numbers (1-31) (integer or string)
+        #   relative day within the month (First, Second, ... Last)
+        #   week days (Sunday, Monday, ... LastDay)
+        VALID_INTERVALS = [
+            "Sunday",
+            "Monday",
+            "Tuesday",
+            "Wednesday",
+            "Thursday",
+            "Friday",
+            "Saturday",
+            "LastDay",
+            "First",
+            "Second",
+            "Third",
+            "Fourth",
+            "Fifth",
+            "Last",
+        ]
+        for value in range(1, 32):
+            VALID_INTERVALS.append(str(value))
+            VALID_INTERVALS.append(value)
+
         for interval_value in interval_values:
-            error = "Invalid interval value for a monthly frequency: {}.".format(interval_value)
-
-            if interval_value != "LastDay":
-                try:
-                    if not (1 <= int(interval_value) <= 31):
-                        raise ValueError(error)
-                except ValueError:
-                    if interval_value != "LastDay":
-                        raise ValueError(error)
+            if interval_value not in VALID_INTERVALS:
+                error = f"Invalid monthly interval: {interval_value}"
+                raise ValueError(error)
 
         self._interval = interval_values
 
diff --git a/tableauserverclient/server/endpoint/endpoint.py b/tableauserverclient/server/endpoint/endpoint.py
index 0e55d5739..be0602df5 100644
--- a/tableauserverclient/server/endpoint/endpoint.py
+++ b/tableauserverclient/server/endpoint/endpoint.py
@@ -144,7 +144,9 @@ def _make_request(
 
         loggable_response = self.log_response_safely(server_response)
         logger.debug("Server response from {0}".format(url))
-        # logger.debug("\n\t{1}".format(loggable_response))
+        # uncomment the following to log full responses in debug mode
+        # BE CAREFUL WHEN SHARING THESE RESULTS - MAY CONTAIN YOUR SENSITIVE DATA
+        # logger.debug(loggable_response)
 
         if content_type == "application/xml":
             self.parent_srv._namespace.detect(server_response.content)
diff --git a/test/assets/schedule_get_monthly_id_2.xml b/test/assets/schedule_get_monthly_id_2.xml
new file mode 100644
index 000000000..ca84297e7
--- /dev/null
+++ b/test/assets/schedule_get_monthly_id_2.xml
@@ -0,0 +1,12 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<tsResponse
+    xmlns="http://tableau.com/api"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://tableau.com/api https://help.tableau.com/samples/en-us/rest_api/ts-api_3_25.xsd">
+    <schedule id="8c5caf33-6223-4724-83c3-ccdc1e730a07" name="Monthly First Monday!" state="Active" priority="50" createdAt="2024-09-12T01:22:07Z" updatedAt="2024-09-12T01:22:48Z" type="Extract" frequency="Monthly" nextRunAt="2024-10-07T08:00:00Z" executionOrder="Parallel">
+        <frequencyDetails start="08:00:00">
+            <intervals>
+                <interval weekDay="Monday" monthDay="First" />
+            </intervals>
+        </frequencyDetails>
+    </schedule>
+</tsResponse>
\ No newline at end of file
diff --git a/test/test_schedule.py b/test/test_schedule.py
index 3bbf5709b..0377295d7 100644
--- a/test/test_schedule.py
+++ b/test/test_schedule.py
@@ -14,6 +14,7 @@
 GET_HOURLY_ID_XML = os.path.join(TEST_ASSET_DIR, "schedule_get_hourly_id.xml")
 GET_DAILY_ID_XML = os.path.join(TEST_ASSET_DIR, "schedule_get_daily_id.xml")
 GET_MONTHLY_ID_XML = os.path.join(TEST_ASSET_DIR, "schedule_get_monthly_id.xml")
+GET_MONTHLY_ID_2_XML = os.path.join(TEST_ASSET_DIR, "schedule_get_monthly_id_2.xml")
 GET_EMPTY_XML = os.path.join(TEST_ASSET_DIR, "schedule_get_empty.xml")
 CREATE_HOURLY_XML = os.path.join(TEST_ASSET_DIR, "schedule_create_hourly.xml")
 CREATE_DAILY_XML = os.path.join(TEST_ASSET_DIR, "schedule_create_daily.xml")
@@ -158,6 +159,21 @@ def test_get_monthly_by_id(self) -> None:
             self.assertEqual("Active", schedule.state)
             self.assertEqual(("1", "2"), schedule.interval_item.interval)
 
+    def test_get_monthly_by_id_2(self) -> None:
+        self.server.version = "3.15"
+        with open(GET_MONTHLY_ID_2_XML, "rb") as f:
+            response_xml = f.read().decode("utf-8")
+        with requests_mock.mock() as m:
+            schedule_id = "8c5caf33-6223-4724-83c3-ccdc1e730a07"
+            baseurl = "{}/schedules/{}".format(self.server.baseurl, schedule_id)
+            m.get(baseurl, text=response_xml)
+            schedule = self.server.schedules.get_by_id(schedule_id)
+            self.assertIsNotNone(schedule)
+            self.assertEqual(schedule_id, schedule.id)
+            self.assertEqual("Monthly First Monday!", schedule.name)
+            self.assertEqual("Active", schedule.state)
+            self.assertEqual(("Monday", "First"), schedule.interval_item.interval)
+
     def test_delete(self) -> None:
         with requests_mock.mock() as m:
             m.delete(self.baseurl + "/c9cff7f9-309c-4361-99ff-d4ba8c9f5467", status_code=204)