Server time display reads each connection's own offset (E5)

src/PlanViewer.App/Controls/QuerySessionControl.Connection.cs

@@ -47,6 +47,14 @@ private async Task ShowConnectionDialogAsync()
             _selectedDatabase = dialog.ResultDatabase;
             _connectionString = _serverConnection.GetConnectionString(_credentialService, _selectedDatabase);
 
+            /* A new holder for a new connection, made here rather than at the fetch below so a
+               document opened while the fetch is still in flight already has the right one to
+               read, and handed to the fetch as a parameter so an offset that lands after ANOTHER
+               reconnect fills this connection's holder and not the newer one's (E5). The
+               connection string is captured for the same reason. */
+            var serverOffset = BeginServerConnection();
+            var offsetConnectionString = _connectionString;
+
             /* A database metadata fetch still running from before this reconnect was built from
                the previous server's connection string. Left alone it can land after
                FetchServerMetadataAsync below has replaced _serverMetadata, and write the old
@@ -81,7 +89,7 @@ whose swallowed failure left a green toolbar over a dead database picker. */
             DatabaseBox.IsEnabled = true;
 
             await FetchServerMetadataAsync();
-            await FetchServerUtcOffset();
+            await FetchServerUtcOffset(offsetConnectionString, serverOffset);
 
             if (_selectedDatabase != null)
             {
@@ -159,18 +167,36 @@ private async Task FetchServerMetadataAsync()
         }
     }
 
-    private async Task FetchServerUtcOffset()
+    /// <summary>
+    /// Starts the offset holder for a new connection. A connect replaces the holder instead of
+    /// reusing it: documents already open keep the old one, because their data came from the old
+    /// server, and documents opened from here on get this one. Internal so a test can connect
+    /// without a server — the connect block calls this and nothing else makes a holder (E5).
+    /// </summary>
+    internal ServerUtcOffset BeginServerConnection()
     {
-        if (_connectionString == null) return;
+        _serverOffset = new ServerUtcOffset();
+        return _serverOffset;
+    }
+
+    /// <summary>
+    /// Asks the server it just connected to for its offset from UTC and fills
+    /// <paramref name="target"/> with it. Takes the connection string and the holder rather than
+    /// reading the session's fields, so the answer lands on the connection that asked even if the
+    /// session has reconnected in the meantime. A failed query leaves the holder at zero.
+    /// </summary>
+    private static async Task FetchServerUtcOffset(string? connectionString, ServerUtcOffset target)
+    {
+        if (connectionString == null) return;
         try
         {
-            await using var conn = new SqlConnection(_connectionString);
+            await using var conn = new SqlConnection(connectionString);
             await conn.OpenAsync();
             await using var cmd = new SqlCommand(
                 "SELECT DATEDIFF(MINUTE, GETUTCDATE(), GETDATE())", conn);
             var offset = await cmd.ExecuteScalarAsync();
             if (offset is int mins)
-                PlanViewer.Core.Services.TimeDisplayHelper.ServerUtcOffsetMinutes = mins;
+                target.Minutes = mins;
         }
         catch { }
     }

src/PlanViewer.App/Controls/QuerySessionControl.QueryStore.cs

@@ -146,14 +146,23 @@ private async Task OpenQueryStoreForDatabaseAsync(string database, DateTime? ini
 
         var databases = DatabaseBox.Items.OfType<string>().ToList();
 
-        var grid = new QueryStoreGridControl(_serverConnection!, _credentialService,
-            database, databases, supportsWaitStats);
+        var grid = NewQueryStoreGrid(database, databases, supportsWaitStats);
         if (initialStartUtc.HasValue && initialEndUtc.HasValue)
             grid.SetInitialTimeRange(initialStartUtc.Value, initialEndUtc.Value);
 
         AddQueryStoreDocument(grid, database);
     }
 
+    /// <summary>
+    /// Builds a Query Store grid on the connection the session is on now, which is what gives it
+    /// that connection's offset holder to keep (E5). Said once because the toolbar's Query Store
+    /// button and the Overview's drill-down both build one, and a second copy of this line is a
+    /// second place to forget the holder. Internal so a test can build one without the server
+    /// check that comes before it in both callers.
+    /// </summary>
+    internal QueryStoreGridControl NewQueryStoreGrid(string database, List<string> databases, bool supportsWaitStats) =>
+        new(_serverConnection!, _credentialService, _serverOffset, database, databases, supportsWaitStats);
+
     /// <summary>
     /// Puts a Query Store grid into the strip as a document and shows it.
     ///
@@ -231,8 +240,7 @@ family as #448. */
         // Build database list from the current DatabaseBox
         var databases = DatabaseBox.Items.OfType<string>().ToList();
 
-        var grid = new QueryStoreGridControl(_serverConnection!, _credentialService,
-            _selectedDatabase!, databases, supportsWaitStats);
+        var grid = NewQueryStoreGrid(_selectedDatabase!, databases, supportsWaitStats);
 
         AddQueryStoreDocument(grid, _selectedDatabase!);
     }

src/PlanViewer.App/Controls/QuerySessionControl.Views.cs

@@ -186,7 +186,7 @@ already reports itself. */
     private QueryStoreOverviewControl BuildOverviewView()
     {
         var supportsWaitStats = _serverMetadata?.SupportsQueryStoreWaitStats ?? false;
-        var overview = new QueryStoreOverviewControl(_serverConnection!, _credentialService,
+        var overview = new QueryStoreOverviewControl(_serverConnection!, _credentialService, _serverOffset,
             supportsWaitStats: supportsWaitStats);
 
         overview.DrillDownRequested += async (_, args) =>

src/PlanViewer.App/Controls/QuerySessionControl.axaml.cs

@@ -105,6 +105,16 @@ public void MarkClean()
     private ServerConnection? _serverConnection;
     private string? _connectionString;
     private string? _selectedDatabase;
+
+    /// <summary>
+    /// The offset from UTC to the server this session is connected to, for Server time display
+    /// (E5). Every connect replaces it (<see cref="BeginServerConnection"/>), and every document
+    /// opened on a connection keeps the one that connection had, so a reconnect — or another
+    /// session on a server in a different time zone — cannot move times that are already on
+    /// screen. Never null: a session that has not connected holds an empty one, which is zero.
+    /// </summary>
+    private ServerUtcOffset _serverOffset = new();
+
     private int _planCounter;
     /// <summary>
     /// The run in flight, or the last one that was: the source of the query or plan capture the

src/PlanViewer.App/Controls/QueryStoreGridControl.Fetch.cs

@@ -169,7 +169,7 @@ private async System.Threading.Tasks.Task FetchFlatPlansAsync(
         }
 
         foreach (var plan in plans)
-            _rows.Add(new QueryStoreRow(plan));
+            _rows.Add(new QueryStoreRow(plan, _serverOffset));
 
         ApplyFilters();
         LoadButton.IsEnabled = true;
@@ -377,7 +377,7 @@ private List<QueryStoreRow> BuildGroupedRows(QueryStoreGroupedResult grouped)
                     {
                         var leafPlan = GroupedRowToPlan(leaf);
                         leafChildren.Add(new QueryStoreRow(leafPlan, 2,
-                            $"Q:{leaf.QueryId} P:{leaf.PlanId}{(leaf.IsTopRepresentative ? " ★" : "")}", new List<QueryStoreRow>()));
+                            $"Q:{leaf.QueryId} P:{leaf.PlanId}{(leaf.IsTopRepresentative ? " ★" : "")}", new List<QueryStoreRow>(), _serverOffset));
                     }
 
                     // Sort leaf children by metric descending
@@ -388,7 +388,7 @@ private List<QueryStoreRow> BuildGroupedRows(QueryStoreGroupedResult grouped)
                     var topLeafForMid = leaves.FirstOrDefault(l => l.IsTopRepresentative) ?? leaves.FirstOrDefault();
                     if (topLeafForMid != null && !string.IsNullOrEmpty(topLeafForMid.QueryText))
                         midPlan.QueryText = topLeafForMid.QueryText;
-                    midChildren.Add(new QueryStoreRow(midPlan, 1, mid.QueryPlanHash, leafChildren));
+                    midChildren.Add(new QueryStoreRow(midPlan, 1, mid.QueryPlanHash, leafChildren, _serverOffset));
                 }
 
                 // Sort mid children by metric descending
@@ -403,7 +403,7 @@ private List<QueryStoreRow> BuildGroupedRows(QueryStoreGroupedResult grouped)
                     ?? grouped.LeafRows.FirstOrDefault(l => l.QueryHash == qhKey && !string.IsNullOrEmpty(l.QueryText));
                 if (topLeafForRoot != null)
                     aggPlan.QueryText = topLeafForRoot.QueryText;
-                roots.Add(new QueryStoreRow(aggPlan, 0, qhKey, midChildren));
+                roots.Add(new QueryStoreRow(aggPlan, 0, qhKey, midChildren, _serverOffset));
             }
         }
         else // Module
@@ -431,7 +431,7 @@ private List<QueryStoreRow> BuildGroupedRows(QueryStoreGroupedResult grouped)
                     {
                         var leafPlan = GroupedRowToPlan(leaf);
                         leafChildren.Add(new QueryStoreRow(leafPlan, 2,
-                            $"Q:{leaf.QueryId} P:{leaf.PlanId}{(leaf.IsTopRepresentative ? " ★" : "")}", new List<QueryStoreRow>()));
+                            $"Q:{leaf.QueryId} P:{leaf.PlanId}{(leaf.IsTopRepresentative ? " ★" : "")}", new List<QueryStoreRow>(), _serverOffset));
                     }
 
                     // Sort leaf children by metric descending
@@ -442,7 +442,7 @@ private List<QueryStoreRow> BuildGroupedRows(QueryStoreGroupedResult grouped)
                     var topLeafForMid = leaves.FirstOrDefault(l => l.IsTopRepresentative) ?? leaves.FirstOrDefault();
                     if (topLeafForMid != null && !string.IsNullOrEmpty(topLeafForMid.QueryText))
                         midPlan.QueryText = topLeafForMid.QueryText;
-                    midChildren.Add(new QueryStoreRow(midPlan, 1, mid.QueryHash, leafChildren));
+                    midChildren.Add(new QueryStoreRow(midPlan, 1, mid.QueryHash, leafChildren, _serverOffset));
                 }
 
                 // Sort mid children by metric descending
@@ -457,7 +457,7 @@ private List<QueryStoreRow> BuildGroupedRows(QueryStoreGroupedResult grouped)
                     ?? grouped.LeafRows.FirstOrDefault(l => l.ModuleName == modKey && !string.IsNullOrEmpty(l.QueryText));
                 if (topLeafForRoot != null)
                     aggPlan.QueryText = topLeafForRoot.QueryText;
-                roots.Add(new QueryStoreRow(aggPlan, 0, modKey, midChildren));
+                roots.Add(new QueryStoreRow(aggPlan, 0, modKey, midChildren, _serverOffset));
             }
         }
 

src/PlanViewer.App/Controls/QueryStoreGridControl.Selection.cs

@@ -94,11 +94,14 @@ private void ViewHistory_Click(object? sender, RoutedEventArgs e)
 
         var metricTag = QueryStoreHistoryWindow.MapOrderByToMetricTag(_lastFetchedOrderBy);
 
+        /* The grid's own holder, not the session's current one: this History reads the grid's
+           server, and the session may have reconnected somewhere else since the grid opened (E5). */
         var control = new QueryStoreHistoryControl(
             _connectionString,
             row.QueryHash,
             row.FullQueryText,
             _database,
+            _serverOffset,
             initialMetricTag: metricTag,
             slicerStartUtc: _slicerStartUtc,
             slicerEndUtc: _slicerEndUtc,
@@ -120,6 +123,7 @@ private void ViewHistory_Click(object? sender, RoutedEventArgs e)
                 row.QueryHash,
                 row.FullQueryText,
                 _database,
+                _serverOffset,
                 initialMetricTag: metricTag,
                 slicerStartUtc: _slicerStartUtc,
                 slicerEndUtc: _slicerEndUtc,

src/PlanViewer.App/Controls/QueryStoreGridControl.Sort.cs

@@ -98,6 +98,8 @@ private void TimeDisplay_SelectionChanged(object? sender, SelectionChangedEventA
         }
         // Refresh slicer labels
         TimeRangeSlicer.Redraw();
+        // Refresh the wait ribbon's labels and tips, which kept the old mode until a resize
+        WaitStatsProfile.RedrawRibbon();
     }
 
     private void UpdateStatusText()

src/PlanViewer.App/Controls/QueryStoreGridControl.axaml.cs

@@ -24,6 +24,12 @@ public partial class QueryStoreGridControl : UserControl
 {
     private readonly ServerConnection _serverConnection;
     private readonly ICredentialService _credentialService;
+    /// <summary>
+    /// The offset holder of the connection this grid was opened on (E5). Kept for the grid's whole
+    /// life and handed to everything it builds — rows, slicer, ribbon, History — because they show
+    /// this server's data, whichever connection the session is on by the time they draw.
+    /// </summary>
+    private readonly ServerUtcOffset _serverOffset;
     private string _connectionString;
     private string _database;
     private CancellationTokenSource? _fetchCts;
@@ -62,10 +68,11 @@ public partial class QueryStoreGridControl : UserControl
     public string Database => _database;
 
     public QueryStoreGridControl(ServerConnection serverConnection, ICredentialService credentialService,
-        string initialDatabase, List<string> databases, bool supportsWaitStats = false)
+        ServerUtcOffset serverOffset, string initialDatabase, List<string> databases, bool supportsWaitStats = false)
     {
         _serverConnection = serverConnection;
         _credentialService = credentialService;
+        _serverOffset = serverOffset;
         _database = initialDatabase;
         _connectionString = serverConnection.GetConnectionString(credentialService, initialDatabase);
         _waitStatsSupported = supportsWaitStats;
@@ -75,6 +82,11 @@ public QueryStoreGridControl(ServerConnection serverConnection, ICredentialServi
 
         InitializeComponent();
 
+        // The slicer and the ribbon are declared in XAML, so they are handed the holder here,
+        // before any data reaches them.
+        TimeRangeSlicer.ServerOffset = serverOffset;
+        WaitStatsProfile.ServerOffset = serverOffset;
+
         // Apply user defaults to UI controls
         TopNBox.Value = userSettings.QueryStoreTopLimit;
         SelectComboByTag(OrderByBox, userSettings.QueryStoreDefaultMetric);
@@ -86,6 +98,11 @@ public QueryStoreGridControl(ServerConnection serverConnection, ICredentialServi
             _ => "query-hash"
         });
 
+        /* The time display mode is one setting for the whole app, so the box opens on the mode in
+           effect. It used to open on Local whatever the setting or another grid had chosen, and
+           could say Local beside times shown in Server mode. The tags are the mode names. */
+        SelectComboByTag(TimeDisplayBox, TimeDisplayHelper.Current.ToString());
+
         // Restore the server-filter panel's expanded state, then subscribe — restoring first
         // means the restore itself never triggers a save.
         ServerFilterExpander.IsExpanded = userSettings.QueryStoreFilterPanelExpanded;
@@ -366,19 +383,26 @@ public class QueryStoreRow : INotifyPropertyChanged
     private bool _isExpanded;
     private int _indentLevel;
 
+    // The connection's offset holder (E5): read each time the row formats its time, so Server
+    // mode shows this row's own server's time whatever else the process is connected to.
+    private readonly ServerUtcOffset _serverOffset;
+
     /// <summary>Standard constructor for flat (ungrouped) rows.</summary>
-    public QueryStoreRow(QueryStorePlan plan)
+    public QueryStoreRow(QueryStorePlan plan, ServerUtcOffset serverOffset)
     {
         Plan = plan;
+        _serverOffset = serverOffset;
     }
 
     /// <summary>Constructor for grouped parent/intermediate rows (aggregated, no single plan).</summary>
-    public QueryStoreRow(QueryStorePlan syntheticPlan, int indentLevel, string groupLabel, List<QueryStoreRow> children)
+    public QueryStoreRow(QueryStorePlan syntheticPlan, int indentLevel, string groupLabel, List<QueryStoreRow> children,
+        ServerUtcOffset serverOffset)
     {
         Plan = syntheticPlan;
         _indentLevel = indentLevel;
         GroupLabel = groupLabel;
         Children = children;
+        _serverOffset = serverOffset;
     }
 
     public QueryStorePlan Plan { get; }
@@ -552,7 +576,7 @@ public double WaitMaxGrandTotal
     public long TotalMemSort => Plan.TotalMemoryGrantPages;
     public double AvgMemSort => Plan.AvgMemoryGrantPages;
 
-    public string LastExecutedLocal => TimeDisplayHelper.FormatForDisplay(Plan.LastExecutedUtc);
+    public string LastExecutedLocal => TimeDisplayHelper.FormatForDisplay(Plan.LastExecutedUtc, _serverOffset.Minutes);
 
     public void NotifyTimeDisplayChanged() => OnPropertyChanged(nameof(LastExecutedLocal));
 

src/PlanViewer.App/Controls/QueryStoreHistoryControl.Chart.cs

@@ -49,7 +49,7 @@ private void UpdateChart()
 			var color = _planHashColorMap.GetValueOrDefault(planHash, PlanColors[0]);
 
 			var ordered = group.OrderBy(r => r.IntervalStartUtc).ToList();
-			var xs = ordered.Select(r => TimeDisplayHelper.ConvertForDisplay(r.IntervalStartUtc).ToOADate()).ToArray();
+			var xs = ordered.Select(r => TimeDisplayHelper.ConvertForDisplay(r.IntervalStartUtc, _serverOffset.Minutes).ToOADate()).ToArray();
 			var ys = ordered.Select(r => GetMetricValue(r, tag)).ToArray();
 
 			var scatter = HistoryChart.Plot.Add.Scatter(xs, ys);
@@ -158,7 +158,7 @@ private void HighlightDotsOnChart(HashSet<int> rowIndices)
 		foreach (var group in groups)
 		{
 			var color = _planHashColorMap.GetValueOrDefault(group.Key, PlanColors[0]);
-			var xs = group.Select(r => TimeDisplayHelper.ConvertForDisplay(r.IntervalStartUtc).ToOADate()).ToArray();
+			var xs = group.Select(r => TimeDisplayHelper.ConvertForDisplay(r.IntervalStartUtc, _serverOffset.Minutes).ToOADate()).ToArray();
 			var ys = group.Select(r => GetMetricValue(r, tag)).ToArray();
 
 			var highlight = HistoryChart.Plot.Add.Scatter(xs, ys);

src/PlanViewer.App/Controls/QueryStoreHistoryControl.Fetch.cs

@@ -46,6 +46,12 @@ private async System.Threading.Tasks.Task LoadHistoryAsync()
 					_connectionString, _queryHash, _maxHoursBack, ct);
 			}
 
+			/* The rows come back from Core, which knows nothing about connections. Each one is given
+			   this control's holder here, before anything binds them, so its own time columns read
+			   the server it was fetched from (E5). */
+			foreach (var row in _historyData)
+				row.ServerOffset = _serverOffset;
+
 			BuildColorMap();
 			HistoryDataGrid.ItemsSource = _historyData;
 			ApplyColorIndicators();
@@ -54,8 +60,8 @@ private async System.Threading.Tasks.Task LoadHistoryAsync()
 			{
 				var planCount = _historyData.Select(r => r.QueryPlanHash).Distinct().Count();
 				var totalExec = _historyData.Sum(r => r.CountExecutions);
-				var first = TimeDisplayHelper.ConvertForDisplay(_historyData.Min(r => r.IntervalStartUtc));
-				var last = TimeDisplayHelper.ConvertForDisplay(_historyData.Max(r => r.IntervalStartUtc));
+				var first = TimeDisplayHelper.ConvertForDisplay(_historyData.Min(r => r.IntervalStartUtc), _serverOffset.Minutes);
+				var last = TimeDisplayHelper.ConvertForDisplay(_historyData.Max(r => r.IntervalStartUtc), _serverOffset.Minutes);
 				StatusText.Text = $"{_historyData.Count} intervals, {planCount} plan(s), " +
 								  $"{totalExec:N0} total executions | " +
 								  $"{first:MM/dd HH:mm} to {last:MM/dd HH:mm}";

src/PlanViewer.App/Controls/QueryStoreHistoryControl.Selection.cs

@@ -128,7 +128,7 @@ private void HandleSingleClickSelection(Point clickPoint)
 			for (int i = 0; i < _historyData.Count; i++)
 			{
 				var row = _historyData[i];
-				var displayTime = TimeDisplayHelper.ConvertForDisplay(row.IntervalStartUtc);
+				var displayTime = TimeDisplayHelper.ConvertForDisplay(row.IntervalStartUtc, _serverOffset.Minutes);
 				if (row.QueryPlanHash == bestPlanHash &&
 					Math.Abs((displayTime - clickedTime).TotalMinutes) < 1)
 				{
@@ -154,7 +154,7 @@ private void HandleBoxSelection(ScottPlot.Coordinates start, ScottPlot.Coordinat
 		for (int i = 0; i < _historyData.Count; i++)
 		{
 			var row = _historyData[i];
-			var xVal = TimeDisplayHelper.ConvertForDisplay(row.IntervalStartUtc).ToOADate();
+			var xVal = TimeDisplayHelper.ConvertForDisplay(row.IntervalStartUtc, _serverOffset.Minutes).ToOADate();
 			var yVal = GetMetricValue(row, tag);
 
 			if (xVal >= x1 && xVal <= x2 && yVal >= y1 && yVal <= y2)