diff --git a/backend/agenteval/intelligent_eval/decision.py b/backend/agenteval/intelligent_eval/decision.py
index ff0c7ad..4611b34 100644
--- a/backend/agenteval/intelligent_eval/decision.py
+++ b/backend/agenteval/intelligent_eval/decision.py
@@ -45,7 +45,7 @@ class Decision:
         }
 
 
-def _parse_time_slot(time_slot: str) -> Optional[tuple[int, int]]:
+def _parse_time_slot(time_slot: str) -> Optional[tuple[float, float]]:
     """Thin wrapper delegating to :func:`agenteval.intelligent_eval.domain.parse_time_slot`."""
     from agenteval.intelligent_eval.domain import parse_time_slot as _impl
     return _impl(time_slot)
diff --git a/backend/agenteval/intelligent_eval/domain.py b/backend/agenteval/intelligent_eval/domain.py
index 4a05e5a..fa4af4c 100644
--- a/backend/agenteval/intelligent_eval/domain.py
+++ b/backend/agenteval/intelligent_eval/domain.py
@@ -21,13 +21,26 @@ from agenteval.storage.db import (
 # ---------------------------------------------------------------------------
 
 
-def parse_time_slot(time_slot: str) -> Optional[tuple[int, int]]:
-    """Parse "8-10h" -> (8, 10). Returns None on bad format."""
+def parse_time_slot(time_slot: str) -> Optional[tuple[float, float]]:
+    """Parse a slot into (start_hours, end_hours), both in hours.
+
+    Supports hour-level ("8-10h" -> (8, 10)) and minute-level ("0-20min" ->
+    (0, 1/3)) slots. planner 对短窗口（如 1h）会用分钟级时段，长窗口用
+    小时级；统一换算成小时（float）供上层判断。Returns None on bad format.
+    """
     try:
-        parts = time_slot.replace("h", "").split("-")
+        raw = time_slot.strip().lower()
+        factor = 1.0
+        if raw.endswith("min"):
+            raw = raw[:-3]
+            factor = 1.0 / 60
+        elif raw.endswith("h"):
+            raw = raw[:-1]
+            factor = 1.0
+        parts = raw.split("-")
         if len(parts) != 2:
             return None
-        return (int(parts[0]), int(parts[1]))
+        return (int(parts[0]) * factor, int(parts[1]) * factor)
     except (ValueError, AttributeError):
         return None
 
diff --git a/tests/unit/test_intelligent_eval_task_queue.py b/tests/unit/test_intelligent_eval_task_queue.py
index 1e3f578..363ea44 100644
--- a/tests/unit/test_intelligent_eval_task_queue.py
+++ b/tests/unit/test_intelligent_eval_task_queue.py
@@ -2,9 +2,6 @@
 
 from datetime import timedelta
 
-import pytest
-from sqlmodel import Session, select
-
 from agenteval.intelligent_eval import task_queue
 from agenteval.intelligent_eval.models import IntelligentEvalStatus
 from agenteval.storage.db import (
@@ -13,6 +10,7 @@ from agenteval.storage.db import (
     IntelligentEvalTaskQueueDB,
     utc_now,
 )
+from sqlmodel import Session, select
 
 
 def test_is_slot_due():
@@ -28,6 +26,25 @@ def test_is_slot_due():
     assert task_queue._is_slot_due({}, timedelta(hours=1)) is False
 
 
+def test_is_slot_due_minute_format():
+    """Minute-level slots (1h window: "0-20min") must be parsed and due on time."""
+    from agenteval.intelligent_eval import domain
+
+    # 0-20min: due at 0min, not before
+    assert task_queue._is_slot_due({"time_slot": "0-20min"}, timedelta(minutes=-1)) is False
+    assert task_queue._is_slot_due({"time_slot": "0-20min"}, timedelta(minutes=0)) is True
+    assert task_queue._is_slot_due({"time_slot": "0-20min"}, timedelta(minutes=5)) is True
+    # 20-40min: not due before 20min, due at 20min
+    assert task_queue._is_slot_due({"time_slot": "20-40min"}, timedelta(minutes=19)) is False
+    assert task_queue._is_slot_due({"time_slot": "20-40min"}, timedelta(minutes=20)) is True
+
+    # parse both formats consistently (hours)
+    assert domain.parse_time_slot("8-10h") == (8.0, 10.0)
+    assert domain.parse_time_slot("0-20min") == (0.0, 1.0 / 3)
+    assert domain.parse_time_slot("20-40min") == (1.0 / 3, 2.0 / 3)
+    assert domain.parse_time_slot("bad") is None
+
+
 def test_calculate_session_deficit(db_session: Session):
     """Test session deficit calculation."""
     # Create eval with plan