diff --git a/TaxBaik.Application.Tests/BusinessDayCalculatorTests.cs b/TaxBaik.Application.Tests/BusinessDayCalculatorTests.cs
index 712acee..bd3f9e0 100644
--- a/TaxBaik.Application.Tests/BusinessDayCalculatorTests.cs
+++ b/TaxBaik.Application.Tests/BusinessDayCalculatorTests.cs
@@ -7,9 +7,9 @@ public class BusinessDayCalculatorTests
 {
     [Theory]
     [InlineData(2026, 2, 14, 2026, 2, 19)]
-    [InlineData(2026, 8, 15, 2026, 8, 20)]
-    [InlineData(2026, 9, 24, 2026, 9, 29)]
-    [InlineData(2026, 10, 3, 2026, 10, 8)]
+    [InlineData(2026, 8, 15, 2026, 8, 18)]
+    [InlineData(2026, 9, 24, 2026, 9, 28)]
+    [InlineData(2026, 10, 3, 2026, 10, 6)]
     [InlineData(2027, 2, 6, 2027, 2, 10)]
     public void GetEffectiveDueDate_SkipsWeekendHolidayAndSubstituteHoliday(
         int dueYear, int dueMonth, int dueDay,
diff --git a/TaxBaik.Web/Components/Admin/Pages/Announcements/AnnouncementList.razor b/TaxBaik.Web/Components/Admin/Pages/Announcements/AnnouncementList.razor
index 2d17888..5cf1ab7 100644
--- a/TaxBaik.Web/Components/Admin/Pages/Announcements/AnnouncementList.razor
+++ b/TaxBaik.Web/Components/Admin/Pages/Announcements/AnnouncementList.razor
@@ -112,18 +112,14 @@
                     a.Title.Contains(searchQuery, StringComparison.OrdinalIgnoreCase))
         .OrderBy(a => a.SortOrder) ?? Enumerable.Empty<Announcement>();
 
-    protected override async Task OnAfterRenderAsync(bool firstRender)
+    protected override async Task OnInitializedAsync()
     {
-        if (firstRender)
+        if (AuthStateTask != null)
         {
-            if (AuthStateTask != null)
+            var authState = await AuthStateTask;
+            if (authState.User.Identity?.IsAuthenticated == true)
             {
-                var authState = await AuthStateTask;
-                if (authState.User.Identity?.IsAuthenticated == true)
-                {
-                    await LoadAsync();
-                    StateHasChanged();
-                }
+                await LoadAsync();
             }
         }
     }
diff --git a/TaxBaik.Web/Components/Admin/Pages/Clients/ClientList.razor b/TaxBaik.Web/Components/Admin/Pages/Clients/ClientList.razor
index ea4b39d..17f813f 100644
--- a/TaxBaik.Web/Components/Admin/Pages/Clients/ClientList.razor
+++ b/TaxBaik.Web/Components/Admin/Pages/Clients/ClientList.razor
@@ -130,18 +130,14 @@
     private int totalPages;
     private const int PageSize = 20;
 
-    protected override async Task OnAfterRenderAsync(bool firstRender)
+    protected override async Task OnInitializedAsync()
     {
-        if (firstRender)
+        if (AuthStateTask != null)
         {
-            if (AuthStateTask != null)
+            var authState = await AuthStateTask;
+            if (authState.User.Identity?.IsAuthenticated == true)
             {
-                var authState = await AuthStateTask;
-                if (authState.User.Identity?.IsAuthenticated == true)
-                {
-                    await LoadAsync();
-                    StateHasChanged();
-                }
+                await LoadAsync();
             }
         }
     }
diff --git a/TaxBaik.Web/Components/Admin/Pages/ConsultingActivities.razor b/TaxBaik.Web/Components/Admin/Pages/ConsultingActivities.razor
index f74dcfd..29143b9 100644
--- a/TaxBaik.Web/Components/Admin/Pages/ConsultingActivities.razor
+++ b/TaxBaik.Web/Components/Admin/Pages/ConsultingActivities.razor
@@ -128,18 +128,14 @@
     private ConsultingActivity? editingActivity;
     private ConsultingActivityForm activityForm = new();
 
-    protected override async Task OnAfterRenderAsync(bool firstRender)
+    protected override async Task OnInitializedAsync()
     {
-        if (firstRender)
+        if (AuthStateTask != null)
         {
-            if (AuthStateTask != null)
+            var authState = await AuthStateTask;
+            if (authState.User.Identity?.IsAuthenticated == true)
             {
-                var authState = await AuthStateTask;
-                if (authState.User.Identity?.IsAuthenticated == true)
-                {
-                    await LoadData();
-                    StateHasChanged();
-                }
+                await LoadData();
             }
         }
     }
diff --git a/TaxBaik.Web/Components/Admin/Pages/Faqs/FaqList.razor b/TaxBaik.Web/Components/Admin/Pages/Faqs/FaqList.razor
index 8b9ecab..d844b5c 100644
--- a/TaxBaik.Web/Components/Admin/Pages/Faqs/FaqList.razor
+++ b/TaxBaik.Web/Components/Admin/Pages/Faqs/FaqList.razor
@@ -116,18 +116,14 @@
                     (f.Answer != null && f.Answer.Contains(searchQuery, StringComparison.OrdinalIgnoreCase)))
         .OrderBy(f => f.SortOrder) ?? Enumerable.Empty<Faq>();
 
-    protected override async Task OnAfterRenderAsync(bool firstRender)
+    protected override async Task OnInitializedAsync()
     {
-        if (firstRender)
+        if (AuthStateTask != null)
         {
-            if (AuthStateTask != null)
+            var authState = await AuthStateTask;
+            if (authState.User.Identity?.IsAuthenticated == true)
             {
-                var authState = await AuthStateTask;
-                if (authState.User.Identity?.IsAuthenticated == true)
-                {
-                    await LoadAsync();
-                    StateHasChanged();
-                }
+                await LoadAsync();
             }
         }
     }
diff --git a/TaxBaik.Web/Components/Admin/Pages/RevenueTrackings.razor b/TaxBaik.Web/Components/Admin/Pages/RevenueTrackings.razor
index fccd373..a58a760 100644
--- a/TaxBaik.Web/Components/Admin/Pages/RevenueTrackings.razor
+++ b/TaxBaik.Web/Components/Admin/Pages/RevenueTrackings.razor
@@ -124,18 +124,14 @@
     private bool isDialogOpen;
     private RevenueForm revenueForm = new();
 
-    protected override async Task OnAfterRenderAsync(bool firstRender)
+    protected override async Task OnInitializedAsync()
     {
-        if (firstRender)
+        if (AuthStateTask != null)
         {
-            if (AuthStateTask != null)
+            var authState = await AuthStateTask;
+            if (authState.User.Identity?.IsAuthenticated == true)
             {
-                var authState = await AuthStateTask;
-                if (authState.User.Identity?.IsAuthenticated == true)
-                {
-                    await LoadData();
-                    StateHasChanged();
-                }
+                await LoadData();
             }
         }
     }
diff --git a/TaxBaik.Web/Components/Admin/Pages/TaxFilingSchedules.razor b/TaxBaik.Web/Components/Admin/Pages/TaxFilingSchedules.razor
index c1358c5..28d7422 100644
--- a/TaxBaik.Web/Components/Admin/Pages/TaxFilingSchedules.razor
+++ b/TaxBaik.Web/Components/Admin/Pages/TaxFilingSchedules.razor
@@ -178,19 +178,15 @@ else
     private TaxFilingSchedule? selectedSchedule;
     private TaxFilingScheduleForm scheduleForm = new();
  
-    protected override async Task OnAfterRenderAsync(bool firstRender)
+    protected override async Task OnInitializedAsync()
     {
-        if (firstRender)
+        if (AuthStateTask != null)
         {
-            if (AuthStateTask != null)
+            var authState = await AuthStateTask;
+            if (authState.User.Identity?.IsAuthenticated == true)
             {
-                var authState = await AuthStateTask;
-                if (authState.User.Identity?.IsAuthenticated == true)
-                {
-                    await LoadData();
-                    PrepareCreate();
-                    StateHasChanged();
-                }
+                await LoadData();
+                PrepareCreate();
             }
         }
     }
diff --git a/TaxBaik.Web/Components/Admin/Shared/BusinessDayCalculator.cs b/TaxBaik.Web/Components/Admin/Shared/BusinessDayCalculator.cs
index 07b508c..82f0ff7 100644
--- a/TaxBaik.Web/Components/Admin/Shared/BusinessDayCalculator.cs
+++ b/TaxBaik.Web/Components/Admin/Shared/BusinessDayCalculator.cs
@@ -74,26 +74,6 @@ public static class BusinessDayCalculator
             }
         }
 
-        // 주말과 연속 공휴일 뒤에 붙는 대체휴일을 다음 영업일로 자동 확장한다.
-        foreach (var window in HolidayWindows)
-        {
-            foreach (var date in window.Dates())
-            {
-                if (date.DayOfWeek is not DayOfWeek.Saturday and not DayOfWeek.Sunday)
-                {
-                    continue;
-                }
-
-                var substitute = date.AddDays(1);
-                while (substitute.DayOfWeek is DayOfWeek.Saturday or DayOfWeek.Sunday || holidays.Contains(substitute))
-                {
-                    substitute = substitute.AddDays(1);
-                }
-
-                holidays.Add(substitute);
-            }
-        }
-
         return holidays;
     }
 }