diff --git a/MyTimeline.py b/MyTimeline.py
index f20b59f..ced5d1b 100644
--- a/MyTimeline.py
+++ b/MyTimeline.py
@@ -115,6 +115,10 @@ YEAR_SELECTOR_SPACING = 5  # Spacing in year selector boxes
 TOOLBAR_SPACING = 5  # Spacing in toolbar
 TOOLBAR_ITEM_MARGIN = 10  # Margin for toolbar items
 TOOLTIP_SEPARATOR_LENGTH = 30  # Length of tooltip separator line
+TOOLTIP_OFFSET = 15  # Offset for tooltip position to avoid cursor
+TOOLTIP_LABEL_MARGIN = 5  # Margin for tooltip label
+TOOLTIP_MAX_WIDTH_CHARS = 40  # Maximum width in characters for tooltip label
+TOOLTIP_BORDER_WIDTH = 8  # Border width for tooltip window
 
 # Font Constants
 FONT_FAMILY = "Sans"
@@ -131,6 +135,14 @@ SHADOW_OFFSET_X = 1
 SHADOW_OFFSET_Y = 1
 SHADOW_OPACITY = 0.3
 BORDER_OPACITY = 0.3
+TIMELINE_SHADOW_OFFSET = 2  # Shadow offset for timeline axis
+
+# Drawing Color Constants
+BACKGROUND_GRADIENT_START = (0.98, 0.98, 0.99)  # Very light gray-blue
+BACKGROUND_GRADIENT_END = (0.95, 0.96, 0.98)  # Slightly darker
+TIMELINE_AXIS_GRADIENT_START = (0.3, 0.3, 0.3)  # Dark gray
+TIMELINE_AXIS_GRADIENT_END = (0.5, 0.5, 0.5)  # Medium gray
+TIMELINE_SHADOW_OPACITY = 0.2  # Shadow opacity for timeline axis
 
 # Connection Line Constants
 CONNECTION_LINE_COLOR = (0.2, 0.5, 1.0, 0.75)  # Brighter, more opaque blue
@@ -468,6 +480,13 @@ class MyTimelineView(NavigationView):
         """
         return "Event"
 
+    def _queue_draw(self) -> None:
+        """
+        Safely queue a redraw of the drawing area if it exists.
+        """
+        if self.drawing_area:
+            self.drawing_area.queue_draw()
+
     def change_page(self) -> None:
         """
         Called when the page changes.
@@ -482,8 +501,7 @@ class MyTimelineView(NavigationView):
             # If no event is selected, ensure timeline is displayed
             if not self.events and self.dbstate.is_open():
                 self.collect_events()
-                if self.drawing_area:
-                    self.drawing_area.queue_draw()
+                self._queue_draw()
 
     def family_updated(self, handle_list: List[str]) -> None:
         """
@@ -494,8 +512,7 @@ class MyTimelineView(NavigationView):
         """
         # Refresh timeline since family updates may affect event display
         self.collect_events()
-        if self.drawing_area:
-            self.drawing_area.queue_draw()
+        self._queue_draw()
 
     def person_updated(self, handle_list: List[str]) -> None:
         """
@@ -506,8 +523,7 @@ class MyTimelineView(NavigationView):
         """
         # Refresh timeline since person updates may affect event display
         self.collect_events()
-        if self.drawing_area:
-            self.drawing_area.queue_draw()
+        self._queue_draw()
 
     def event_updated(self, handle_list: List[str]) -> None:
         """
@@ -518,8 +534,7 @@ class MyTimelineView(NavigationView):
         """
         # Re-collect events when events are updated
         self.collect_events()
-        if self.drawing_area:
-            self.drawing_area.queue_draw()
+        self._queue_draw()
         
         # If the active event was updated, ensure it's still highlighted
         if self.active_event_handle in handle_list:
@@ -547,8 +562,7 @@ class MyTimelineView(NavigationView):
             db.connect("person-update", self.person_updated)
             db.connect("event-update", self.event_updated)
         
-        if self.drawing_area:
-            self.drawing_area.queue_draw()
+        self._queue_draw()
 
     def build_widget(self) -> Gtk.Widget:
         """
@@ -761,11 +775,11 @@ class MyTimelineView(NavigationView):
         
         # Main content area
         content_area = dialog.get_content_area()
-        content_area.set_spacing(10)
-        content_area.set_margin_start(10)
-        content_area.set_margin_end(10)
-        content_area.set_margin_top(10)
-        content_area.set_margin_bottom(10)
+        content_area.set_spacing(FILTER_PAGE_SPACING)
+        content_area.set_margin_start(FILTER_PAGE_MARGIN)
+        content_area.set_margin_end(FILTER_PAGE_MARGIN)
+        content_area.set_margin_top(FILTER_PAGE_MARGIN)
+        content_area.set_margin_bottom(FILTER_PAGE_MARGIN)
         
         # Notebook for organizing filters
         notebook = Gtk.Notebook()
@@ -1079,6 +1093,21 @@ class MyTimelineView(NavigationView):
         scrolled.add(box)
         return scrolled
 
+    def _set_validation_message(self, message: str) -> None:
+        """
+        Set the date validation label message.
+        
+        Args:
+            message: Message text to display (empty string to clear).
+        """
+        if hasattr(self, 'date_validation_label'):
+            if message:
+                self.date_validation_label.set_markup(
+                    f"<span color='red'>{message}</span>"
+                )
+            else:
+                self.date_validation_label.set_text("")
+
     def _update_year_spin_button(self, spin_key: str, year: int, handler: Callable) -> None:
         """
         Update a year spin button value, blocking signals during update.
@@ -1271,8 +1300,7 @@ class MyTimelineView(NavigationView):
             self._update_year_spin_button('date_to_year_spin', now.year, self._on_to_year_changed)
         
         # Clear validation message
-        if hasattr(self, 'date_validation_label'):
-            self.date_validation_label.set_text("")
+        self._set_validation_message("")
 
     def _update_filter_dialog_state(self) -> None:
         """
@@ -1353,10 +1381,7 @@ class MyTimelineView(NavigationView):
             
             if from_date is None or to_date is None:
                 # Show error message for invalid dates
-                if hasattr(self, 'date_validation_label'):
-                    self.date_validation_label.set_markup(
-                        f"<span color='red'>{_('Error: Invalid date in date range filter')}</span>"
-                    )
+                self._set_validation_message(_('Error: Invalid date in date range filter'))
                 logger.warning("Error parsing date range in filter dialog: invalid date from calendar")
                 self.date_range_filter = None
                 self.date_range_explicit = False
@@ -1368,17 +1393,13 @@ class MyTimelineView(NavigationView):
             # Validate date range
             if min_sort > max_sort:
                 # Show error message
-                if hasattr(self, 'date_validation_label'):
-                    self.date_validation_label.set_markup(
-                        f"<span color='red'>{_('Error: From date must be before To date')}</span>"
-                    )
+                self._set_validation_message(_('Error: From date must be before To date'))
                 self.date_range_filter = None
                 self.date_range_explicit = False
                 return
             else:
                 # Clear error message
-                if hasattr(self, 'date_validation_label'):
-                    self.date_validation_label.set_text("")
+                self._set_validation_message("")
                 
                 # Set filter - user has selected dates in calendars
                 self.date_range_filter = (min_sort, max_sort)
@@ -1576,8 +1597,7 @@ class MyTimelineView(NavigationView):
                 to_year_spin.handler_unblock_by_func(self._on_to_year_changed)
             
             # Clear validation message
-            if hasattr(self, 'date_validation_label'):
-                self.date_validation_label.set_text("")
+            self._set_validation_message("")
             
             # Mark that date range should not be applied
             self.date_range_explicit = False
@@ -1595,23 +1615,21 @@ class MyTimelineView(NavigationView):
         from_year, from_month, from_day = from_calendar.get_date()
         to_year, to_month, to_day = to_calendar.get_date()
         
+        # Use helper method to create dates
+        from_date = self._create_date_from_calendar(from_calendar)
+        to_date = self._create_date_from_calendar(to_calendar)
+        
+        if from_date is None or to_date is None:
+            return
+        
         try:
-            from_date = Date()
-            from_date.set_yr_mon_day(from_year, from_month + 1, from_day)
             from_sort = from_date.get_sort_value()
-            
-            to_date = Date()
-            to_date.set_yr_mon_day(to_year, to_month + 1, to_day)
             to_sort = to_date.get_sort_value()
             
             if from_sort > to_sort:
-                if hasattr(self, 'date_validation_label'):
-                    self.date_validation_label.set_markup(
-                        f"<span color='red'>{_('Warning: From date is after To date')}</span>"
-                    )
+                self._set_validation_message(_('Warning: From date is after To date'))
             else:
-                if hasattr(self, 'date_validation_label'):
-                    self.date_validation_label.set_text("")
+                self._set_validation_message("")
         except (ValueError, AttributeError, TypeError):
             pass
 
@@ -1627,8 +1645,8 @@ class MyTimelineView(NavigationView):
         active_handle = self.get_active()
         if active_handle:
             self.goto_handle(active_handle)
-        elif self.drawing_area:
-            self.drawing_area.queue_draw()
+        else:
+            self._queue_draw()
 
     def goto_handle(self, handle: str) -> None:
         """
@@ -1647,8 +1665,7 @@ class MyTimelineView(NavigationView):
             self.collect_events()
         else:
             # Just refresh display to highlight the selected event
-            if self.drawing_area:
-                self.drawing_area.queue_draw()
+            self._queue_draw()
         
         # Scroll to the selected event if possible
         self._scroll_to_event(handle)
@@ -2175,8 +2192,7 @@ class MyTimelineView(NavigationView):
             self.events = self._apply_filters(self.all_events)
             self._invalidate_cache()
             self._calculate_timeline_height()
-            if self.drawing_area:
-                self.drawing_area.queue_draw()
+            self._queue_draw()
 
     def _calculate_date_range(self) -> Tuple[int, int, int]:
         """
@@ -2418,8 +2434,7 @@ class MyTimelineView(NavigationView):
         self.zoom_level = level
         self.update_zoom_display()
         self._recalculate_timeline_height()
-        if self.drawing_area:
-            self.drawing_area.queue_draw()
+        self._queue_draw()
 
     def on_zoom_in(self, widget: Gtk.Widget) -> None:
         """
@@ -2518,7 +2533,7 @@ class MyTimelineView(NavigationView):
                         self.selected_person_handles.add(person_handle)
                         # Color will be assigned when drawing
                 
-                self.drawing_area.queue_draw()
+                self._queue_draw()
         return False
 
     def on_motion_notify(self, widget: Gtk.Widget, event: Gdk.Event) -> bool:
@@ -2557,7 +2572,7 @@ class MyTimelineView(NavigationView):
                     TOOLTIP_DELAY, self.show_tooltip, hovered_index, event.x_root, event.y_root
                 )
             
-            self.drawing_area.queue_draw()
+            self._queue_draw()
         
         return False
 
@@ -2584,7 +2599,7 @@ class MyTimelineView(NavigationView):
             self.tooltip_window.destroy()
             self.tooltip_window = None
         
-        self.drawing_area.queue_draw()
+        self._queue_draw()
         return False
 
     def _get_cache_key(self, timeline_y_start: float, timeline_y_end: float) -> int:
@@ -2782,7 +2797,7 @@ class MyTimelineView(NavigationView):
         """
         if not hasattr(self, 'tooltip_window') or self.tooltip_window is None:
             self.tooltip_window = Gtk.Window(type=Gtk.WindowType.POPUP)
-            self.tooltip_window.set_border_width(8)
+            self.tooltip_window.set_border_width(TOOLTIP_BORDER_WIDTH)
             self.tooltip_window.set_decorated(False)
             
             # Get parent window for proper display
@@ -2838,18 +2853,18 @@ class MyTimelineView(NavigationView):
         label = Gtk.Label()
         label.set_markup(tooltip_text)
         label.set_line_wrap(True)
-        label.set_max_width_chars(40)
-        label.set_margin_start(5)
-        label.set_margin_end(5)
-        label.set_margin_top(5)
-        label.set_margin_bottom(5)
+        label.set_max_width_chars(TOOLTIP_MAX_WIDTH_CHARS)
+        label.set_margin_start(TOOLTIP_LABEL_MARGIN)
+        label.set_margin_end(TOOLTIP_LABEL_MARGIN)
+        label.set_margin_top(TOOLTIP_LABEL_MARGIN)
+        label.set_margin_bottom(TOOLTIP_LABEL_MARGIN)
         
         frame.add(label)
         tooltip_window.add(frame)
         tooltip_window.show_all()
         
         # Position tooltip (offset to avoid cursor)
-        tooltip_window.move(int(x_root) + 15, int(y_root) + 15)
+        tooltip_window.move(int(x_root) + TOOLTIP_OFFSET, int(y_root) + TOOLTIP_OFFSET)
         
         return False
 
@@ -2863,8 +2878,8 @@ class MyTimelineView(NavigationView):
             height: Widget height.
         """
         pattern = cairo.LinearGradient(0, 0, 0, height)
-        pattern.add_color_stop_rgb(0, 0.98, 0.98, 0.99)  # Very light gray-blue
-        pattern.add_color_stop_rgb(1, 0.95, 0.96, 0.98)  # Slightly darker
+        pattern.add_color_stop_rgb(0, *BACKGROUND_GRADIENT_START)
+        pattern.add_color_stop_rgb(1, *BACKGROUND_GRADIENT_END)
         context.set_source(pattern)
         context.paint()
 
@@ -2897,16 +2912,16 @@ class MyTimelineView(NavigationView):
             y_end: Y coordinate of the timeline end.
         """
         # Draw shadow
-        context.set_source_rgba(0.0, 0.0, 0.0, 0.2)
+        context.set_source_rgba(0.0, 0.0, 0.0, TIMELINE_SHADOW_OPACITY)
         context.set_line_width(TIMELINE_LINE_WIDTH)
-        context.move_to(timeline_x + 2, y_start + 2)
-        context.line_to(timeline_x + 2, y_end + 2)
+        context.move_to(timeline_x + TIMELINE_SHADOW_OFFSET, y_start + TIMELINE_SHADOW_OFFSET)
+        context.line_to(timeline_x + TIMELINE_SHADOW_OFFSET, y_end + TIMELINE_SHADOW_OFFSET)
         context.stroke()
 
         # Draw main line with gradient
         pattern = cairo.LinearGradient(timeline_x, y_start, timeline_x, y_end)
-        pattern.add_color_stop_rgb(0, 0.3, 0.3, 0.3)
-        pattern.add_color_stop_rgb(1, 0.5, 0.5, 0.5)
+        pattern.add_color_stop_rgb(0, *TIMELINE_AXIS_GRADIENT_START)
+        pattern.add_color_stop_rgb(1, *TIMELINE_AXIS_GRADIENT_END)
         context.set_source(pattern)
         context.set_line_width(TIMELINE_LINE_WIDTH)
         context.move_to(timeline_x, y_start)