diff --git a/app/services/metrics.py b/app/services/metrics.py
index 2f7c11a..25293a1 100644
--- a/app/services/metrics.py
+++ b/app/services/metrics.py
@@ -71,6 +71,75 @@ def _overlap_minutes(
     return minutes_between(start, end) if end > start else 0.0
 
 
+def _clip_interval(
+    interval_start: datetime,
+    interval_end: datetime,
+    boundary_start: datetime,
+    boundary_end: datetime,
+) -> tuple[datetime, datetime] | None:
+    start = max(interval_start, boundary_start)
+    end = min(interval_end, boundary_end)
+    if end <= start:
+        return None
+    return start, end
+
+
+def _merge_intervals(intervals: list[tuple[datetime, datetime]]) -> list[tuple[datetime, datetime]]:
+    ordered = sorted(intervals, key=lambda item: item[0])
+    merged: list[tuple[datetime, datetime]] = []
+    for start, end in ordered:
+        if not merged or start > merged[-1][1]:
+            merged.append((start, end))
+        elif end > merged[-1][1]:
+            merged[-1] = (merged[-1][0], end)
+    return merged
+
+
+def _subtract_intervals(
+    base_start: datetime,
+    base_end: datetime,
+    occupied: list[tuple[datetime, datetime]],
+) -> list[tuple[datetime, datetime]]:
+    gaps: list[tuple[datetime, datetime]] = []
+    cursor = base_start
+    for start, end in _merge_intervals(occupied):
+        if start > cursor:
+            gaps.append((cursor, start))
+        if end > cursor:
+            cursor = end
+    if cursor < base_end:
+        gaps.append((cursor, base_end))
+    return gaps
+
+
+def _calendar_dates_between(start_at: datetime, end_at: datetime):
+    current = start_at.date()
+    last = end_at.date()
+    while current <= last:
+        yield current
+        current += timedelta(days=1)
+
+
+def _blank_overtime_intervals(
+    current_date: date,
+    schedule: WorkScheduleConfig,
+) -> list[tuple[datetime, datetime]]:
+    day_start = datetime.combine(current_date, time.min)
+    day_end = day_start + timedelta(days=1)
+    occupied: list[tuple[datetime, datetime]] = []
+    raw_intervals = [
+        _schedule_interval(current_date, schedule.day_start, schedule.day_end),
+        _schedule_interval(current_date, schedule.overtime_start, schedule.overtime_end),
+        _schedule_interval(current_date, schedule.night_start, schedule.night_end),
+        _schedule_interval(current_date - timedelta(days=1), schedule.night_start, schedule.night_end),
+    ]
+    for interval_start, interval_end in raw_intervals:
+        clipped = _clip_interval(interval_start, interval_end, day_start, day_end)
+        if clipped is not None:
+            occupied.append(clipped)
+    return _subtract_intervals(day_start, day_end, occupied)
+
+
 def _covered_meal_overlap_minutes(
     start_at: datetime,
     end_at: datetime,
@@ -143,6 +212,21 @@ def _raw_shift_minutes(
                     )
                 )
                 minutes[bucket] += max(0.0, raw_minutes - meal_minutes)
+
+        for blank_start, blank_end in _blank_overtime_intervals(current_date, active_schedule):
+            raw_minutes = _overlap_minutes(start_at, end_at, blank_start, blank_end)
+            blank_start_at = max(start_at, blank_start)
+            blank_end_at = min(end_at, blank_end)
+            meal_minutes = sum(
+                _overlap_minutes(blank_start_at, blank_end_at, meal_start, meal_end)
+                for meal_start, meal_end in meal_intervals
+                if (
+                    start_at <= meal_start
+                    and end_at >= meal_end
+                    and end_at > meal_end + timedelta(minutes=MEAL_END_GRACE_MINUTES)
+                )
+            )
+            minutes["overtime"] += max(0.0, raw_minutes - meal_minutes)
     return minutes
 
 
diff --git a/tests/test_metrics.py b/tests/test_metrics.py
index 46271d8..b1ab1e7 100644
--- a/tests/test_metrics.py
+++ b/tests/test_metrics.py
@@ -280,3 +280,33 @@ def test_admin_forced_release_still_caps_work_time():
     assert metrics["duration_minutes"] == 60
     assert metrics["effective_minutes"] == 60
     assert item.allocated_minutes == 60
+
+
+def test_morning_blank_interval_counts_as_overtime():
+    start_at = datetime(2026, 7, 25, 6, 0, 0)
+    end_at = datetime(2026, 7, 25, 8, 0, 0)
+    item = Item(good_qty=10)
+
+    metrics = calculate_report_metrics(start_at, end_at, [item])
+
+    assert metrics["duration_minutes"] == 120
+    assert metrics["effective_minutes"] == 120
+    assert metrics["shift_day_minutes"] == 0
+    assert metrics["shift_overtime_minutes"] == 120
+    assert metrics["shift_night_minutes"] == 0
+    assert item.allocated_minutes == 120
+
+
+def test_dinner_blank_interval_counts_as_overtime():
+    start_at = datetime(2026, 7, 25, 17, 20, 0)
+    end_at = datetime(2026, 7, 25, 18, 0, 0)
+    item = Item(good_qty=10)
+
+    metrics = calculate_report_metrics(start_at, end_at, [item])
+
+    assert metrics["duration_minutes"] == 40
+    assert metrics["effective_minutes"] == 40
+    assert metrics["shift_day_minutes"] == 0
+    assert metrics["shift_overtime_minutes"] == 40
+    assert metrics["shift_night_minutes"] == 0
+    assert item.allocated_minutes == 40