diff --git a/Dashboard/CollectorScheduleWindow.xaml b/Dashboard/CollectorScheduleWindow.xaml
index e002f72d..ee370e21 100644
--- a/Dashboard/CollectorScheduleWindow.xaml
+++ b/Dashboard/CollectorScheduleWindow.xaml
@@ -40,8 +40,8 @@
                     <DataGridTextColumn Header="Collector" Binding="{Binding DisplayName}" Width="180" IsReadOnly="True"/>
                     <DataGridTextColumn Header="Frequency (min)" Binding="{Binding FrequencyMinutes, Mode=TwoWay, UpdateSourceTrigger=LostFocus}" Width="110"/>
                     <DataGridTextColumn Header="Retention (days)" Binding="{Binding RetentionDays, Mode=TwoWay, UpdateSourceTrigger=LostFocus}" Width="110"/>
-                    <DataGridTextColumn Header="Last Run" Binding="{Binding LastRunTime, StringFormat='{}{0:MM/dd HH:mm}'}" Width="100" IsReadOnly="True"/>
-                    <DataGridTextColumn Header="Next Run" Binding="{Binding NextRunTime, StringFormat='{}{0:MM/dd HH:mm}'}" Width="100" IsReadOnly="True"/>
+                    <DataGridTextColumn Header="Last Run" Binding="{Binding LastRunTime, StringFormat='{}{0:g}'}" Width="100" IsReadOnly="True"/>
+                    <DataGridTextColumn Header="Next Run" Binding="{Binding NextRunTime, StringFormat='{}{0:g}'}" Width="100" IsReadOnly="True"/>
                     <DataGridTextColumn Header="Description" Binding="{Binding Description}" Width="*" IsReadOnly="True"/>
                 </DataGrid.Columns>
             </DataGrid>
diff --git a/Dashboard/ManageServersWindow.xaml b/Dashboard/ManageServersWindow.xaml
index 8f83ad24..9c279c8c 100644
--- a/Dashboard/ManageServersWindow.xaml
+++ b/Dashboard/ManageServersWindow.xaml
@@ -50,7 +50,7 @@
                     <DataGridTextColumn Header="Display Name" Binding="{Binding DisplayName}" Width="150"/>
                     <DataGridTextColumn Header="Server" Binding="{Binding ServerName}" Width="180"/>
                     <DataGridTextColumn Header="Authentication" Binding="{Binding AuthenticationDisplay}" Width="120"/>
-                    <DataGridTextColumn Header="Last Connected" Binding="{Binding LastConnected, StringFormat='{}{0:MM/dd/yyyy HH:mm}'}" Width="130"/>
+                    <DataGridTextColumn Header="Last Connected" Binding="{Binding LastConnected, StringFormat='{}{0:g}'}" Width="130"/>
                 </DataGrid.Columns>
             </DataGrid>
         </Border>
diff --git a/Dashboard/Models/ServerConnectionStatus.cs b/Dashboard/Models/ServerConnectionStatus.cs
index 15f84571..5000dd14 100644
--- a/Dashboard/Models/ServerConnectionStatus.cs
+++ b/Dashboard/Models/ServerConnectionStatus.cs
@@ -7,7 +7,6 @@
  */
 
 using System;
-using System.Globalization;
 
 namespace PerformanceMonitorDashboard.Models
 {
@@ -127,7 +126,7 @@ public string LastCheckedDisplay
                 if (elapsed.TotalHours < 24)
                     return $"Checked {(int)elapsed.TotalHours}h ago";
 
-                return $"Checked {LastChecked.Value.ToString("MMM d, h:mm tt", CultureInfo.CurrentCulture)}";
+                return $"Checked {LastChecked.Value.ToString("g")}";
             }
         }
 
@@ -147,7 +146,7 @@ public string StatusDurationDisplay
                 {
                     if (ServerStartTime.HasValue)
                     {
-                        return $"Online since {ServerStartTime.Value.ToString("MMM d, h:mm tt", CultureInfo.CurrentCulture)}";
+                        return $"Online since {ServerStartTime.Value.ToString("g")}";
                     }
                     return "Online";
                 }
diff --git a/Dashboard/ServerTab.xaml.cs b/Dashboard/ServerTab.xaml.cs
index 1d54bc03..3bff0a9d 100644
--- a/Dashboard/ServerTab.xaml.cs
+++ b/Dashboard/ServerTab.xaml.cs
@@ -172,7 +172,7 @@ private void InitializeTimeComboBoxes()
             for (int h = 0; h < 24; h++)
             {
                 var dt = DateTime.Today.AddHours(h);
-                hours.Add(dt.ToString("h tt")); // "12 AM", "1 AM", ..., "11 PM"
+                hours.Add(dt.ToString("HH:00")); // "00:00", "01:00", ..., "23:00"
             }
 
             GlobalFromHour.ItemsSource = hours;
diff --git a/Lite/Controls/ServerTab.xaml.cs b/Lite/Controls/ServerTab.xaml.cs
index 4e30cdae..40f7877a 100644
--- a/Lite/Controls/ServerTab.xaml.cs
+++ b/Lite/Controls/ServerTab.xaml.cs
@@ -144,7 +144,7 @@ private void InitializeTimeComboBoxes()
         for (int h = 0; h < 24; h++)
         {
             var dt = DateTime.Today.AddHours(h);
-            hours.Add(dt.ToString("h tt")); // "12 AM", "1 AM", ..., "11 PM"
+            hours.Add(dt.ToString("HH:00")); // "00:00", "01:00", ..., "23:00"
         }
 
         FromHourCombo.ItemsSource = hours;
diff --git a/Lite/Models/ServerConnectionStatus.cs b/Lite/Models/ServerConnectionStatus.cs
index 16977173..3bb56012 100644
--- a/Lite/Models/ServerConnectionStatus.cs
+++ b/Lite/Models/ServerConnectionStatus.cs
@@ -7,7 +7,6 @@
  */
 
 using System;
-using System.Globalization;
 
 namespace PerformanceMonitorLite.Models;
 
@@ -146,7 +145,7 @@ public string LastCheckedDisplay
             if (elapsed.TotalHours < 24)
                 return $"Checked {(int)elapsed.TotalHours}h ago";
 
-            return $"Checked {LastChecked.Value.ToString("MMM d, h:mm tt", CultureInfo.CurrentCulture)}";
+            return $"Checked {LastChecked.Value.ToString("g")}";
         }
     }
 
@@ -166,7 +165,7 @@ public string StatusDurationDisplay
             {
                 if (ServerStartTime.HasValue)
                 {
-                    return $"Online since {ServerStartTime.Value.ToString("MMM d, h:mm tt", CultureInfo.CurrentCulture)}";
+                    return $"Online since {ServerStartTime.Value.ToString("g")}";
                 }
                 return "Online";
             }
diff --git a/Lite/Services/LocalDataService.CollectionHealth.cs b/Lite/Services/LocalDataService.CollectionHealth.cs
index c30557cf..8a5da51a 100644
--- a/Lite/Services/LocalDataService.CollectionHealth.cs
+++ b/Lite/Services/LocalDataService.CollectionHealth.cs
@@ -122,7 +122,7 @@ public class CollectionLogRow
     public string Status { get; set; } = "";
     public string? ErrorMessage { get; set; }
 
-    public string CollectionTimeFormatted => CollectionTime.ToLocalTime().ToString("MM/dd HH:mm:ss");
+    public string CollectionTimeFormatted => CollectionTime.ToLocalTime().ToString("g");
 
     public string DurationFormatted => DurationMs.HasValue
         ? (DurationMs.Value < 1000 ? $"{DurationMs.Value} ms" : $"{DurationMs.Value / 1000.0:F1} s")
@@ -167,15 +167,15 @@ public string HealthStatus
         : $"{AvgDurationMs / 1000:F1} s";
 
     public string LastSuccessFormatted => LastSuccessTime.HasValue
-        ? LastSuccessTime.Value.ToLocalTime().ToString("MM/dd HH:mm:ss")
+        ? LastSuccessTime.Value.ToLocalTime().ToString("g")
         : "Never";
 
     public string LastRunFormatted => LastRunTime.HasValue
-        ? LastRunTime.Value.ToLocalTime().ToString("MM/dd HH:mm:ss")
+        ? LastRunTime.Value.ToLocalTime().ToString("g")
         : "Never";
 
     public string LastErrorFormatted => LastErrorTime.HasValue
-        ? LastErrorTime.Value.ToLocalTime().ToString("MM/dd HH:mm:ss")
+        ? LastErrorTime.Value.ToLocalTime().ToString("g")
         : "";
 }