diff --git a/src/TaxBaik.Web.Client/Components/Admin/Pages/ClientLogs.razor b/src/TaxBaik.Web.Client/Components/Admin/Pages/ClientLogs.razor
index 21e30d1..610d676 100644
--- a/src/TaxBaik.Web.Client/Components/Admin/Pages/ClientLogs.razor
+++ b/src/TaxBaik.Web.Client/Components/Admin/Pages/ClientLogs.razor
@@ -23,24 +23,6 @@
                 <div><strong>Info</strong> @_summary.InfoCount</div>
             </div>
         }
-        @if (_groups.Count > 0)
-        {
-            <div class="admin-log-group-list">
-                @foreach (var group in _groups)
-                {
-                    <article class="admin-log-group-item">
-                        <div class="admin-log-item-header">
-                            <strong>@group.Count</strong>
-                            <span>@group.Level</span>
-                            <span>@group.Source</span>
-                            <span>@group.Route</span>
-                        </div>
-                        <p>@group.Message</p>
-                        <small>@group.LastSeen</small>
-                    </article>
-                }
-            </div>
-        }
         <div class="admin-log-filter-row">
             <input class="mud-input-slot" placeholder="검색어" @bind="_query" @bind:event="oninput" />
             <select class="mud-input-slot" @bind="_level">
@@ -49,6 +31,8 @@
                 <option value="warning">warning</option>
                 <option value="info">info</option>
             </select>
+            <input class="mud-input-slot" placeholder="시작 ISO 시각" @bind="_start" @bind:event="oninput" />
+            <input class="mud-input-slot" placeholder="종료 ISO 시각" @bind="_end" @bind:event="oninput" />
             <button type="button" class="mud-button-root" @onclick="LoadAsync">새로고침</button>
         </div>
         @if (_loading)
@@ -76,6 +60,27 @@
                 }
             </div>
         }
+        @if (_groups.Count > 0)
+        {
+            <details class="admin-log-group-details">
+                <summary>반복 오류 그룹 보기</summary>
+                <div class="admin-log-group-list">
+                    @foreach (var group in _groups)
+                    {
+                        <article class="admin-log-group-item">
+                            <div class="admin-log-item-header">
+                                <strong>@group.Count</strong>
+                                <span>@group.Level</span>
+                                <span>@group.Source</span>
+                                <span>@group.Route</span>
+                            </div>
+                            <p>@group.Message</p>
+                            <small>@group.LastSeen</small>
+                        </article>
+                    }
+                </div>
+            </details>
+        }
     </div>
 </section>
 
@@ -85,6 +90,8 @@
     private bool _loading = true;
     private string _query = "";
     private string _level = "";
+    private string _start = "";
+    private string _end = "";
     private ClientLogSummaryDto? _summary;
 
     protected override async Task OnInitializedAsync()
@@ -101,7 +108,7 @@
         try
         {
             _summary = await Http.GetFromJsonAsync<ClientLogSummaryDto>("/taxbaik/api/client-logs/summary");
-            var url = $"/taxbaik/api/client-logs/recent?q={Uri.EscapeDataString(_query ?? string.Empty)}&level={Uri.EscapeDataString(_level ?? string.Empty)}";
+            var url = $"/taxbaik/api/client-logs/recent?q={Uri.EscapeDataString(_query ?? string.Empty)}&level={Uri.EscapeDataString(_level ?? string.Empty)}&start={Uri.EscapeDataString(_start ?? string.Empty)}&end={Uri.EscapeDataString(_end ?? string.Empty)}";
             var result = await Http.GetFromJsonAsync<List<ClientLogDto>>(url);
             var grouped = await Http.GetFromJsonAsync<List<ClientLogGroupDto>>("/taxbaik/api/client-logs/groups");
             if (result is not null)
diff --git a/src/TaxBaik.Web/Endpoints/ClientLogs/GetRecentLogsEndpoint.cs b/src/TaxBaik.Web/Endpoints/ClientLogs/GetRecentLogsEndpoint.cs
index 52a0937..a333b0f 100644
--- a/src/TaxBaik.Web/Endpoints/ClientLogs/GetRecentLogsEndpoint.cs
+++ b/src/TaxBaik.Web/Endpoints/ClientLogs/GetRecentLogsEndpoint.cs
@@ -5,6 +5,7 @@ namespace TaxBaik.Web.Endpoints.ClientLogs;
 public sealed class RecentClientLogEntry
 {
     public string? Timestamp { get; set; }
+    public DateTimeOffset? OccurredAt { get; set; }
     public string? Level { get; set; }
     public string? Source { get; set; }
     public string? Message { get; set; }
@@ -37,6 +38,8 @@ public sealed class GetRecentLogsEndpoint : EndpointWithoutRequest<IReadOnlyList
         var source = Query<string>("source");
         var route = Query<string>("route");
         var term = Query<string>("q");
+        var start = ParseDate(Query<string>("start"));
+        var end = ParseDate(Query<string>("end"));
 
         var logDir = Path.Combine(_environment.ContentRootPath, "logs");
         if (!Directory.Exists(logDir))
@@ -60,7 +63,7 @@ public sealed class GetRecentLogsEndpoint : EndpointWithoutRequest<IReadOnlyList
                     continue;
 
                 var entry = Parse(line);
-                if (Matches(entry, level, source, route, term))
+                if (Matches(entry, level, source, route, term, start, end))
                     entries.Add(entry);
             }
         }
@@ -70,18 +73,21 @@ public sealed class GetRecentLogsEndpoint : EndpointWithoutRequest<IReadOnlyList
 
     private static RecentClientLogEntry Parse(string line)
     {
-        var entry = new RecentClientLogEntry();
-        entry.Timestamp = ExtractTimestamp(line);
-        entry.Level = ExtractBetween(line, "] [", "]");
-        entry.Source = ExtractTokenAfter(line, "ClientLog ", 1);
-        entry.Route = ExtractNamedValue(line, "Route=");
-        entry.Screen = ExtractNamedValue(line, "Screen=");
-        entry.Feature = ExtractNamedValue(line, "Feature=");
-        entry.Action = ExtractNamedValue(line, "Action=");
-        entry.Step = ExtractNamedValue(line, "Step=");
-        entry.BuildVersion = ExtractNamedValue(line, "BuildVersion=");
-        entry.Message = ExtractMessage(line);
-        return entry;
+        var timestamp = ExtractTimestamp(line);
+        return new RecentClientLogEntry
+        {
+            Timestamp = timestamp,
+            OccurredAt = ParseDate(timestamp),
+            Level = ExtractBetween(line, "] [", "]"),
+            Source = ExtractTokenAfter(line, "ClientLog ", 1),
+            Route = ExtractNamedValue(line, "Route="),
+            Screen = ExtractNamedValue(line, "Screen="),
+            Feature = ExtractNamedValue(line, "Feature="),
+            Action = ExtractNamedValue(line, "Action="),
+            Step = ExtractNamedValue(line, "Step="),
+            BuildVersion = ExtractNamedValue(line, "BuildVersion="),
+            Message = ExtractMessage(line)
+        };
     }
 
     private static string? ExtractTimestamp(string line)
@@ -120,7 +126,7 @@ public sealed class GetRecentLogsEndpoint : EndpointWithoutRequest<IReadOnlyList
         return clientIndex >= 0 ? line[(clientIndex + "ClientLog ".Length)..] : line;
     }
 
-    private static bool Matches(RecentClientLogEntry entry, string? level, string? source, string? route, string? term)
+    private static bool Matches(RecentClientLogEntry entry, string? level, string? source, string? route, string? term, DateTimeOffset? start, DateTimeOffset? end)
     {
         if (!string.IsNullOrWhiteSpace(level) &&
             !string.Equals(entry.Level, level, StringComparison.OrdinalIgnoreCase))
@@ -147,9 +153,29 @@ public sealed class GetRecentLogsEndpoint : EndpointWithoutRequest<IReadOnlyList
             return false;
         }
 
+        if (start is not null && (entry.OccurredAt is null || entry.OccurredAt < start))
+        {
+            return false;
+        }
+
+        if (end is not null && (entry.OccurredAt is null || entry.OccurredAt > end))
+        {
+            return false;
+        }
+
         return true;
     }
 
+    private static DateTimeOffset? ParseDate(string? value)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+        {
+            return null;
+        }
+
+        return DateTimeOffset.TryParse(value, out var parsed) ? parsed : null;
+    }
+
     private static string? ExtractNamedValue(string text, string prefix)
     {
         var index = text.IndexOf(prefix, StringComparison.OrdinalIgnoreCase);