diff --git a/module/ocr/ocr.py b/module/ocr/ocr.py
index 09810e3ff..c46f80886 100644
--- a/module/ocr/ocr.py
+++ b/module/ocr/ocr.py
@@ -145,6 +145,12 @@ class Ocr:
                     text=str([result for result, _ in result_list]))
         return result_list
 
+    def filter_detected(self, result: BoxedResult) -> bool:
+        """
+        Return False to drop result.
+        """
+        return True
+
     def detect_and_ocr(self, image, direct_ocr=False) -> list[BoxedResult]:
         """
         Args:
@@ -160,13 +166,14 @@ class Ocr:
             image = crop(image, self.button.area)
         image = self.pre_process(image)
         # ocr
-        # image = enlarge_canvas(image)
         results: list[BoxedResult] = self.model.detect_and_ocr(image)
         # after proces
         for result in results:
             if not direct_ocr:
                 result.box += self.button.area[:2]
             result.box = tuple(corner2area(result.box))
+
+        results = [result for result in results if self.filter_detected(result)]
         results = merge_buttons(results, thres_x=self.merge_thres_x, thres_y=self.merge_thres_y)
         for result in results:
             result.ocr_text = self.after_process(result.ocr_text)
@@ -366,14 +373,18 @@ class Duration(Ocr):
     @classmethod
     def timedelta_regex(cls, lang):
         regex_str = {
-            'cn': r'((?P<days>\d{1,2})天)?'
+            'cn': r'^(?P<prefix>.*?)'
+                  r'((?P<days>\d{1,2})天)?'
                   r'((?P<hours>\d{1,2})小时)?'
                   r'((?P<minutes>\d{1,2})分钟)?'
-                  r'((?P<seconds>\d{1,2})秒)',
-            'en': r'((?P<days>\d{1,2})\s*d\s*)?'
+                  r'((?P<seconds>\d{1,2})秒)?'
+                  r'$',
+            'en': r'^(?P<prefix>.*?)'
+                  r'((?P<days>\d{1,2})\s*d\s*)?'
                   r'((?P<hours>\d{1,2})\s*h\s*)?'
                   r'((?P<minutes>\d{1,2})\s*m\s*)?'
-                  r'((?P<seconds>\d{1,2})\s*s)'
+                  r'((?P<seconds>\d{1,2})\s*s)?'
+                  r'$'
         }[lang]
         return re.compile(regex_str)
 
diff --git a/tasks/assignment/ui.py b/tasks/assignment/ui.py
index b7270218e..fc4a62b7b 100644
--- a/tasks/assignment/ui.py
+++ b/tasks/assignment/ui.py
@@ -60,16 +60,13 @@ class AssignmentOcr(Ocr):
             return None
         return re.compile('|'.join('(?P<%s>%s)' % pair for pair in rules))
 
+    def filter_detected(self, result) -> bool:
+        # Drop duration rows
+        res = Duration.timedelta_regex(self.lang).search(result.ocr_text)
+        return not bool(res.group('seconds'))
+
     def after_process(self, result: str):
         result = super().after_process(result)
-        # Drop duration
-        result = Duration.timedelta_regex(self.lang).sub('', result)
-        result = result.strip()
-
-        if self.lang == 'cn':
-            # Hourglass icon may be detected as "豆"
-            result = result.replace('豆', '')
-            result = re.sub(r'\d$', '', result)
 
         if self.ocr_regex is None:
             return result