diff --git a/homeassistant/components/saunum/climate.py b/homeassistant/components/saunum/climate.py
index 52fb7ed0212..a6e55ccfe34 100644
--- a/homeassistant/components/saunum/climate.py
+++ b/homeassistant/components/saunum/climate.py
@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import asyncio
+from datetime import timedelta
 from typing import Any
 
 from pysaunum import MAX_TEMPERATURE, MIN_TEMPERATURE, SaunumException
@@ -241,9 +242,9 @@ class LeilSaunaClimate(LeilSaunaEntity, ClimateEntity):
 
     async def async_start_session(
         self,
-        duration: int = 120,
+        duration: timedelta = timedelta(minutes=120),
         target_temperature: int = 80,
-        fan_duration: int = 10,
+        fan_duration: timedelta = timedelta(minutes=10),
     ) -> None:
         """Start a sauna session with custom parameters."""
         if self.coordinator.data.door_open:
@@ -254,11 +255,15 @@ class LeilSaunaClimate(LeilSaunaEntity, ClimateEntity):
 
         try:
             # Set all parameters before starting the session
-            await self.coordinator.client.async_set_sauna_duration(duration)
+            await self.coordinator.client.async_set_sauna_duration(
+                int(duration.total_seconds() // 60)
+            )
             await self.coordinator.client.async_set_target_temperature(
                 target_temperature
             )
-            await self.coordinator.client.async_set_fan_duration(fan_duration)
+            await self.coordinator.client.async_set_fan_duration(
+                int(fan_duration.total_seconds() // 60)
+            )
             await self.coordinator.client.async_start_session()
         except SaunumException as err:
             raise HomeAssistantError(
diff --git a/homeassistant/components/saunum/services.py b/homeassistant/components/saunum/services.py
index 0a86da8386d..88b074af15d 100644
--- a/homeassistant/components/saunum/services.py
+++ b/homeassistant/components/saunum/services.py
@@ -2,6 +2,8 @@
 
 from __future__ import annotations
 
+from datetime import timedelta
+
 from pysaunum import MAX_DURATION, MAX_FAN_DURATION, MAX_TEMPERATURE, MIN_TEMPERATURE
 import voluptuous as vol
 
@@ -27,14 +29,22 @@ def async_setup_services(hass: HomeAssistant) -> None:
         SERVICE_START_SESSION,
         entity_domain=CLIMATE_DOMAIN,
         schema={
-            vol.Optional(ATTR_DURATION, default=120): vol.All(
-                cv.positive_int, vol.Range(min=1, max=MAX_DURATION)
+            vol.Optional(ATTR_DURATION, default=timedelta(minutes=120)): vol.All(
+                cv.time_period,
+                vol.Range(
+                    min=timedelta(minutes=1),
+                    max=timedelta(minutes=MAX_DURATION),
+                ),
             ),
             vol.Optional(ATTR_TARGET_TEMPERATURE, default=80): vol.All(
                 cv.positive_int, vol.Range(min=MIN_TEMPERATURE, max=MAX_TEMPERATURE)
             ),
-            vol.Optional(ATTR_FAN_DURATION, default=10): vol.All(
-                cv.positive_int, vol.Range(min=1, max=MAX_FAN_DURATION)
+            vol.Optional(ATTR_FAN_DURATION, default=timedelta(minutes=10)): vol.All(
+                cv.time_period,
+                vol.Range(
+                    min=timedelta(minutes=1),
+                    max=timedelta(minutes=MAX_FAN_DURATION),
+                ),
             ),
         },
         func="async_start_session",
diff --git a/tests/components/saunum/test_services.py b/tests/components/saunum/test_services.py
index 0229df1b66b..798b495b148 100644
--- a/tests/components/saunum/test_services.py
+++ b/tests/components/saunum/test_services.py
@@ -1,8 +1,9 @@
 """Tests for Saunum services."""
 
+from dataclasses import replace
 from unittest.mock import MagicMock
 
-from pysaunum import SaunumData, SaunumException
+from pysaunum import SaunumException
 import pytest
 
 from homeassistant.components.saunum.const import DOMAIN
@@ -36,9 +37,9 @@ async def test_start_session_success(
         SERVICE_START_SESSION,
         {
             ATTR_ENTITY_ID: "climate.saunum_leil",
-            ATTR_DURATION: 120,
+            ATTR_DURATION: {"hours": 2, "minutes": 0, "seconds": 0},
             ATTR_TARGET_TEMPERATURE: 80,
-            ATTR_FAN_DURATION: 10,
+            ATTR_FAN_DURATION: {"minutes": 10},
         },
         blocking=True,
     )
@@ -73,11 +74,10 @@ async def test_start_session_door_open(
     hass: HomeAssistant,
     mock_config_entry: MockConfigEntry,
     mock_saunum_client: MagicMock,
-    mock_saunum_data: SaunumData,
 ) -> None:
     """Test start_session service fails when door is open."""
-    mock_saunum_client.async_get_data.return_value = SaunumData(
-        **{**mock_saunum_data.__dict__, "door_open": True}
+    mock_saunum_client.async_get_data.return_value = replace(
+        mock_saunum_client.async_get_data.return_value, door_open=True
     )
     mock_config_entry.add_to_hass(hass)
     await hass.config_entries.async_setup(mock_config_entry.entry_id)