diff --git a/routes/import_routes.py b/routes/import_routes.py
index 83bafd5..787e3e6 100644
--- a/routes/import_routes.py
+++ b/routes/import_routes.py
@@ -21,6 +21,7 @@ from config import BASE_DIR
 from database.manager import DatabaseManager
 from database.models import MonthlySummaryAnalysis
 from services.logger_manager import SystemLogger
+from utils.text_helpers import extract_snapshot_date_from_filename as _extract_snapshot_date_from_filename
 from utils.validators import validate_upload_file
 
 # 時區設定
@@ -47,21 +48,6 @@ def _get_cache_refs():
     return _SALES_DF_CACHE, _SALES_PROCESSED_CACHE, clear_sales_cache_for_table
 
 
-def _extract_snapshot_date_from_filename(filename):
-    """從檔名提取日期：即時業績_當日_20260111.xlsx → 2026-01-11"""
-    match = re.search(r'(\d{8})', filename)
-    if match:
-        date_str = match.group(1)
-        try:
-            year = date_str[:4]
-            month = date_str[4:6]
-            day = date_str[6:8]
-            return f"{year}-{month}-{day}"
-        except:
-            return None
-    return None
-
-
 def _safe_read_sql(table_name, engine):
     """安全的 SQL 讀取函數"""
     from utils.validators import safe_read_sql
diff --git a/tests/test_snapshot_date_helpers.py b/tests/test_snapshot_date_helpers.py
new file mode 100644
index 0000000..0643317
--- /dev/null
+++ b/tests/test_snapshot_date_helpers.py
@@ -0,0 +1,18 @@
+from pathlib import Path
+
+from utils.text_helpers import extract_snapshot_date_from_filename
+
+
+def test_extract_snapshot_date_from_filename_valid_date():
+    assert extract_snapshot_date_from_filename("即時業績_當日_20260111.xlsx") == "2026-01-11"
+
+
+def test_extract_snapshot_date_from_filename_rejects_invalid_date():
+    assert extract_snapshot_date_from_filename("即時業績_當日_20261399.xlsx") is None
+
+
+def test_import_routes_uses_shared_snapshot_date_helper():
+    source = Path("routes/import_routes.py").read_text(encoding="utf-8")
+
+    assert "except:" not in source
+    assert "extract_snapshot_date_from_filename as _extract_snapshot_date_from_filename" in source
diff --git a/utils/text_helpers.py b/utils/text_helpers.py
index 11d0df5..473725d 100644
--- a/utils/text_helpers.py
+++ b/utils/text_helpers.py
@@ -4,6 +4,7 @@
 """
 import hashlib
 import re
+from datetime import datetime
 
 
 def slugify(text):
@@ -43,11 +44,8 @@ def extract_snapshot_date_from_filename(filename):
         return None
     date_str = match.group(1)
     try:
-        year = date_str[:4]
-        month = date_str[4:6]
-        day = date_str[6:8]
-        return f"{year}-{month}-{day}"
-    except Exception:
+        return datetime.strptime(date_str, "%Y%m%d").date().isoformat()
+    except ValueError:
         return None