Add categories support to subdivision holidays methods (#1446)

holidays/holiday_base.py

@@ -648,14 +648,19 @@ def _add_holiday(self, name: str, *args) -> Optional[date]:
         self[dt] = self.tr(name)
         return dt
 
-    def _add_subdiv_holidays(self):
-        """Populate subdivision holidays."""
+    def _add_subdiv_category_holidays(self, category: str = None):
+        """Populate subdivision holidays by category."""
         if self.subdiv is not None:
             subdiv = self.subdiv.replace("-", "_").replace(" ", "_").lower()
-            add_subdiv_holidays = getattr(self, f"_add_subdiv_{subdiv}_holidays", None)
+            method_name = f"_add_subdiv_{subdiv}{f'_{category}' if category else ''}_holidays"
+            add_subdiv_holidays = getattr(self, method_name, None)
             if add_subdiv_holidays and callable(add_subdiv_holidays):
                 add_subdiv_holidays()
 
+    def _add_subdiv_holidays(self):
+        """Populate subdivision holidays."""
+        self._add_subdiv_category_holidays()
+
     def _add_substituted_holidays(self):
         """Populate substituted holidays."""
         if len(self.substituted_holidays) == 0:
@@ -758,6 +763,9 @@ def _populate_categories(self):
             if populate_category_holidays and callable(populate_category_holidays):
                 populate_category_holidays()
 
+            # Populate subdivision holidays for all categories.
+            self._add_subdiv_category_holidays(category)
+
     def append(self, *args: Union[Dict[DateLike, str], List[DateLike], DateLike]) -> None:
         """Alias for :meth:`update` to mimic list type."""
         return self.update(*args)