diff --git a/custom_components/localthings/registry/capabilities/operational.py b/custom_components/localthings/registry/capabilities/operational.py
index 6970140..193efb9 100644
--- a/custom_components/localthings/registry/capabilities/operational.py
+++ b/custom_components/localthings/registry/capabilities/operational.py
@@ -90,7 +90,14 @@ def _finish_time(rep):
     total_s = _remaining_seconds(rep.get('x.com.samsung.da.remainingTime'))
     if not total_s:
         return None
-    return datetime.now(timezone.utc) + timedelta(seconds=total_s)
+    # Round to whole minutes -- remainingTime itself only has minute
+    # resolution, but datetime.now() always carries fresh seconds/
+    # microseconds, so an unrounded result changes on nearly every poll
+    # even when the device-reported remaining time hasn't. That floods
+    # the recorder history/logbook with values that look identical once
+    # the UI rounds them down for display.
+    finish = datetime.now(timezone.utc) + timedelta(seconds=total_s)
+    return finish.replace(second=0, microsecond=0)
 
 
 def _completion_minutes(rep):
diff --git a/tests/test_operational_capability.py b/tests/test_operational_capability.py
index 606efb6..5f50535 100644
--- a/tests/test_operational_capability.py
+++ b/tests/test_operational_capability.py
@@ -62,6 +62,34 @@ class TestCompletionMinutes:
         assert desc.rep_fn(rep) is None
 
 
+class TestFinishTime:
+    """issue: remainingTime only has minute resolution, but datetime.now()
+    always carries fresh seconds/microseconds -- an unrounded finish_time
+    changed on nearly every poll even when remainingTime hadn't, flooding
+    the recorder history/logbook with values that looked identical once
+    the UI rounded them down to the minute for display."""
+
+    def test_seconds_and_microseconds_are_zeroed(self):
+        desc = next(e for e in OPERATIONAL_STATE.entities if e.key == 'finish_time')
+        rep = {
+            'x.com.samsung.da.state': 'Run',
+            'x.com.samsung.da.remainingTime': '00:29:00',
+        }
+        result = desc.rep_fn(rep)
+        assert result.second == 0
+        assert result.microsecond == 0
+
+    def test_stable_across_polls_within_same_minute(self):
+        desc = next(e for e in OPERATIONAL_STATE.entities if e.key == 'finish_time')
+        rep = {
+            'x.com.samsung.da.state': 'Run',
+            'x.com.samsung.da.remainingTime': '00:29:00',
+        }
+        first = desc.rep_fn(rep)
+        second = desc.rep_fn(rep)
+        assert first == second
+
+
 class TestDelayFieldFallback:
     def test_reads_delay_end_time_when_delay_start_time_absent(self):
         from custom_components.localthings.registry.capabilities.operational import OPERATIONAL_STATE