diff --git a/miio/airqualitymonitor.py b/miio/airqualitymonitor.py
index 075e9b55d..71cf51d03 100644
--- a/miio/airqualitymonitor.py
+++ b/miio/airqualitymonitor.py
@@ -28,21 +28,39 @@ def usb_power(self) -> bool:
 
     @property
     def aqi(self) -> int:
-        """Air quality index value."""
+        """Air quality index value. (0...600)."""
         return self.data["aqi"]
 
     @property
     def battery(self) -> int:
-        """Current battery level."""
+        """Current battery level (0...100)."""
         return self.data["battery"]
 
+    @property
+    def time_state(self) -> str:
+        """Current time state."""
+        return self.data["time_state"]
+
+    def __repr__(self) -> str:
+        s = "<AirQualityMonitorStatus power=%s, " \
+            "aqi=%s, " \
+            "battery=%s, " \
+            "usb=%s, " \
+            "time_state=%s>" % \
+            (self.power,
+             self.aqi,
+             self.battery,
+             self.usb,
+             self.time_state)
+        return s
+
 
 class AirQualityMonitor(Device):
     """Xiaomi PM2.5 Air Quality Monitor."""
     def status(self) -> AirQualityMonitorStatus:
         """Return device status."""
 
-        properties = ['power', 'aqi', 'battery', 'usb_state']
+        properties = ['power', 'aqi', 'battery', 'usb_state', 'time_state']
 
         values = self.send(
             "get_prop",
diff --git a/miio/tests/test_airqualitymonitor.py b/miio/tests/test_airqualitymonitor.py
index 243bf6015..578599d53 100644
--- a/miio/tests/test_airqualitymonitor.py
+++ b/miio/tests/test_airqualitymonitor.py
@@ -10,7 +10,8 @@ def __init__(self, *args, **kwargs):
             'power': 'on',
             'aqi': 34,
             'battery': 100,
-            'usb_state': 'off'
+            'usb_state': 'off',
+            'time_state': 'format unknown'
         }
         self.return_values = {
             'get_prop': self._get_state,
@@ -56,3 +57,4 @@ def test_status(self):
         assert self.state().aqi == self.device.start_state["aqi"]
         assert self.state().battery == self.device.start_state["battery"]
         assert self.state().usb_power == (self.device.start_state["usb_state"] == 'on')
+        assert self.state().time_state == self.device.start_state["time_state"]