diff --git a/src/managers/AllDayManager.ts b/src/managers/AllDayManager.ts
index 1083ad4..474437a 100644
--- a/src/managers/AllDayManager.ts
+++ b/src/managers/AllDayManager.ts
@@ -242,7 +242,7 @@ export class AllDayManager {
           { height: `${currentSpacerHeight}px` },
           { height: `${targetSpacerHeight}px` }
         ], {
-          duration: 300,
+          duration: 150,
           easing: 'ease-out',
           fill: 'forwards'
         })
diff --git a/src/managers/NavigationManager.ts b/src/managers/NavigationManager.ts
index 180d1d0..f03c9b4 100644
--- a/src/managers/NavigationManager.ts
+++ b/src/managers/NavigationManager.ts
@@ -270,6 +270,29 @@ export class NavigationManager {
       newGrid.style.position = 'relative';
       newGrid.removeAttribute('data-prerendered');
       
+      // Reset all-day height and remove hardcoded header height after slide animation
+      const root = document.documentElement;
+      root.style.setProperty('--all-day-row-height', '0px');
+      
+      const header = newGrid.querySelector('swp-calendar-header') as HTMLElement;
+      if (header) {
+          // Remove the hardcoded 0px height
+          header.style.height = '';
+          header.style.height
+          // NOW emit header:ready for this specific container
+          const weekEnd = DateCalculator.addDays(targetWeek, 6);
+          this.eventBus.emit('header:ready', {
+              headerElement: header,
+              startDate: targetWeek,
+              endDate: weekEnd,
+              isNavigation: true
+          });
+          
+          console.log('🎯 NavigationManager: Animation complete, emitted header:ready', {
+              weekStart: targetWeek.toISOString()
+          });
+      }
+      
       // Clear cache since DOM structure changed
       this.clearCache();
       
diff --git a/src/renderers/NavigationRenderer.ts b/src/renderers/NavigationRenderer.ts
index 396a011..572afc0 100644
--- a/src/renderers/NavigationRenderer.ts
+++ b/src/renderers/NavigationRenderer.ts
@@ -137,6 +137,19 @@ export class NavigationRenderer {
       </swp-scrollable-content>
     `;
 
+    // Set header to base height for slide-in animation - will be reset after animation completes
+    const header = newGrid.querySelector('swp-calendar-header') as HTMLElement;
+    if (header) {
+        // Get base header height (without all-day rows)
+        const root = document.documentElement;
+        const baseHeaderHeight = getComputedStyle(root).getPropertyValue('--header-height');
+        header.style.height = baseHeaderHeight;
+        console.log('🔄 NavigationRenderer: Set header height to base height for slide-in', {
+            baseHeaderHeight,
+            weekStart: weekStart.toISOString()
+        });
+    }
+
     // Position new grid - NO transform here, let Animation API handle it
     newGrid.style.position = 'absolute';
     newGrid.style.top = '0';
@@ -214,7 +227,7 @@ export class NavigationRenderer {
       endDate: weekEnd,
       isNavigation: true
     };
-    this.eventBus.emit('header:ready', payload);
+    //this.eventBus.emit('header:ready', payload);
   }
 
   /**