Fix browser-timezone session date filters (#1245)

Session list and sidebar calendar-date filters now accept the browser IANA timezone, default omitted values to UTC, and reject invalid zones.

Local calendar dates are translated into DST-aware UTC boundaries while preserving latest-message activity fallback and equivalent SQLite, PostgreSQL, and DuckDB query behavior. The sidebar sends the browser timezone on initial and paginated requests, and the generated API client reflects the new parameter.

Fixes #1232.

Co-authored-by: Gabriel Mitelman Tkacz <gtkacz@users.noreply.github.com>

Author: gtkacz

frontend/src/lib/api/generated/services/SearchService.ts

@@ -381,6 +381,7 @@ class SessionsStore {
       date: f.date || undefined,
       dateFrom: f.dateFrom || undefined,
       dateTo: f.dateTo || undefined,
+      timezone: Intl.DateTimeFormat().resolvedOptions().timeZone,
       activeSince: f.recentlyActive
         ? new Date(
             Date.now() - 24 * 60 * 60 * 1000,

frontend/src/lib/api/generated/services/SessionsService.ts

@@ -222,7 +222,13 @@ describe("SessionsStore", () => {
   let sessions: ReturnType<typeof createSessionsStore>;
 
   beforeEach(() => {
+    vi.restoreAllMocks();
     vi.clearAllMocks();
+    const resolvedOptions = Intl.DateTimeFormat().resolvedOptions();
+    vi.spyOn(Intl.DateTimeFormat.prototype, "resolvedOptions").mockReturnValue({
+      ...resolvedOptions,
+      timeZone: "America/New_York",
+    });
     vi.mocked(callGenerated).mockImplementation(
       (request: () => Promise<unknown>) => request(),
     );
@@ -1559,6 +1565,14 @@ describe("SessionsStore", () => {
   });
 
   describe("load serialization", () => {
+    it("should pass the browser timezone", async () => {
+      await sessions.load();
+
+      expectSidebarIndexCalledWith({
+        timezone: "America/New_York",
+      });
+    });
+
     it("should omit min/max_messages when 0", async () => {
       sessions.filters.minMessages = 0;
       sessions.filters.maxMessages = 0;
@@ -1668,6 +1682,17 @@ describe("SessionsStore", () => {
   });
 
   describe("loadMore serialization", () => {
+    it("should pass the browser timezone in loadMore", async () => {
+      sessions.nextCursor = "cur-timezone";
+
+      mockSidebarPage();
+      await sessions.loadMore();
+
+      expectPaginatedSidebarIndexCalledWith({
+        timezone: "America/New_York",
+      });
+    });
+
     it("should load the sidebar index once with consistent filters", async () => {
       mockSidebarIndex([
         makeSkinnyRow({ id: "s1" }),

frontend/src/lib/stores/sessions.svelte.ts

@@ -870,23 +870,23 @@ func TestSessionDateFilterIncludesOverlappingSessions(t *testing.T) {
 	d := testDB(t)
 
 	insertSession(t, d, "before", "proj", func(s *Session) {
-		s.StartedAt = new("2024-06-15T08:00:00Z")
-		s.EndedAt = new("2024-06-15T09:00:00Z")
+		s.StartedAt = new("2024-06-16T02:00:00Z")
+		s.EndedAt = new("2024-06-16T03:59:59Z")
 		s.MessageCount = 2
 	})
 	insertSession(t, d, "spanning", "proj", func(s *Session) {
-		s.StartedAt = new("2024-06-15T23:00:00Z")
+		s.StartedAt = new("2024-06-16T03:00:00Z")
 		s.EndedAt = new("2024-06-16T10:00:00Z")
 		s.MessageCount = 2
 	})
 	insertSession(t, d, "open", "proj", func(s *Session) {
-		s.StartedAt = new("2024-06-15T22:00:00Z")
+		s.StartedAt = new("2024-06-16T02:00:00Z")
 		s.MessageCount = 2
 	})
-	seedMessage(t, d, "open", 1, "user", "2024-06-16T11:00:00Z", "")
+	seedMessage(t, d, "open", 1, "user", "2024-06-17T03:59:59Z", "")
 	insertSession(t, d, "after", "proj", func(s *Session) {
-		s.StartedAt = new("2024-06-17T08:00:00Z")
-		s.EndedAt = new("2024-06-17T09:00:00Z")
+		s.StartedAt = new("2024-06-17T04:00:00Z")
+		s.EndedAt = new("2024-06-17T05:00:00Z")
 		s.MessageCount = 2
 	})
 	insertSession(t, d, "child", "proj", func(s *Session) {
@@ -903,24 +903,33 @@ func TestSessionDateFilterIncludesOverlappingSessions(t *testing.T) {
 		want   []string
 	}{
 		{
-			name:   "ExactDate",
-			filter: SessionFilter{Date: "2024-06-16"},
-			want:   []string{"spanning", "open"},
+			name: "ExactDate",
+			filter: SessionFilter{
+				Date: "2024-06-16", Timezone: "America/New_York",
+			},
+			want: []string{"spanning", "open"},
 		},
 		{
-			name:   "DateRange",
-			filter: SessionFilter{DateFrom: "2024-06-16", DateTo: "2024-06-16"},
-			want:   []string{"spanning", "open"},
+			name: "DateRange",
+			filter: SessionFilter{
+				DateFrom: "2024-06-16", DateTo: "2024-06-16",
+				Timezone: "America/New_York",
+			},
+			want: []string{"spanning", "open"},
 		},
 		{
-			name:   "DateFrom",
-			filter: SessionFilter{DateFrom: "2024-06-16"},
-			want:   []string{"spanning", "open", "after"},
+			name: "DateFrom",
+			filter: SessionFilter{
+				DateFrom: "2024-06-16", Timezone: "America/New_York",
+			},
+			want: []string{"spanning", "open", "after"},
 		},
 		{
-			name:   "DateTo",
-			filter: SessionFilter{DateTo: "2024-06-15"},
-			want:   []string{"before", "spanning", "open"},
+			name: "DateTo",
+			filter: SessionFilter{
+				DateTo: "2024-06-15", Timezone: "America/New_York",
+			},
+			want: []string{"before", "spanning", "open"},
 		},
 	}
 
@@ -931,7 +940,7 @@ func TestSessionDateFilterIncludesOverlappingSessions(t *testing.T) {
 	}
 
 	index, err := d.GetSidebarSessionIndex(context.Background(), SessionFilter{
-		Date: "2024-06-16",
+		Date: "2024-06-16", Timezone: "America/New_York",
 	})
 	require.NoError(t, err, "GetSidebarSessionIndex")
 	requireSidebarIndexIDs(t, index.Sessions, []string{

frontend/src/lib/stores/sessions.test.ts

@@ -35,7 +35,6 @@ type QueryDialect struct {
 	dateStartExpr      func(func(string) string) string
 	dateEndExpr        func(func(string) string) string
 	dateParam          func(string) string
-	activityExpr       string
 	activityParam      func(string) string
 	cursorActivityExpr string
 	cursorParam        func(string) string
@@ -71,18 +70,18 @@ func SQLiteQueryDialect() QueryDialect {
 		trueLiteral:      "1",
 		falseLiteral:     "0",
 		dateStartExpr: func(q func(string) string) string {
-			return "date(COALESCE(NULLIF(" + q("started_at") +
+			return "julianday(COALESCE(NULLIF(" + q("started_at") +
 				", ''), " + q("created_at") + "))"
 		},
 		dateEndExpr: func(q func(string) string) string {
-			return "date(COALESCE(NULLIF(" + q("ended_at") +
-				", ''), (SELECT MAX(m.timestamp) FROM messages m" +
+			return "julianday(COALESCE(NULLIF(" + q("ended_at") +
+				", ''), (SELECT m.timestamp FROM messages m" +
 				" WHERE m.session_id = " + outerSessionID(q) +
-				" AND m.timestamp != ''), NULLIF(" + q("started_at") +
+				" AND m.timestamp != '' ORDER BY julianday(m.timestamp)" +
+				" DESC, m.timestamp DESC LIMIT 1), NULLIF(" + q("started_at") +
 				", ''), " + q("created_at") + "))"
 		},
-		dateParam:              func(ph string) string { return ph },
-		activityExpr:           "COALESCE(NULLIF(ended_at, ''), NULLIF(started_at, ''), created_at)",
+		dateParam:              func(ph string) string { return "julianday(" + ph + ")" },
 		activityParam:          func(ph string) string { return ph },
 		cursorActivityExpr:     "COALESCE(NULLIF(ended_at, ''), NULLIF(started_at, ''), created_at)",
 		cursorParam:            func(ph string) string { return ph },
@@ -109,18 +108,17 @@ func PostgresQueryDialect() QueryDialect {
 		trueLiteral:      "TRUE",
 		falseLiteral:     "FALSE",
 		dateStartExpr: func(q func(string) string) string {
-			return "DATE(COALESCE(" + q("started_at") + ", " +
-				q("created_at") + ") AT TIME ZONE 'UTC')"
+			return "COALESCE(" + q("started_at") + ", " +
+				q("created_at") + ")"
 		},
 		dateEndExpr: func(q func(string) string) string {
-			return "DATE(COALESCE(" + q("ended_at") +
+			return "COALESCE(" + q("ended_at") +
 				", (SELECT MAX(m.timestamp) FROM messages m" +
 				" WHERE m.session_id = " + outerSessionID(q) +
 				" AND m.timestamp IS NOT NULL), " + q("started_at") +
-				", " + q("created_at") + ") AT TIME ZONE 'UTC')"
+				", " + q("created_at") + ")"
 		},
-		dateParam:    func(ph string) string { return ph + "::date" },
-		activityExpr: "COALESCE(ended_at, started_at, created_at)",
+		dateParam: func(ph string) string { return ph + "::timestamptz" },
 		activityParam: func(ph string) string {
 			return ph + "::timestamptz"
 		},
@@ -152,19 +150,18 @@ func DuckDBQueryDialect() QueryDialect {
 		falseLiteral:     "FALSE",
 		dateStartExpr: func(q func(string) string) string {
 			return "CAST(COALESCE(" + q("started_at") + ", " +
-				q("created_at") + ") AS DATE)"
+				q("created_at") + ") AS TIMESTAMP)"
 		},
 		dateEndExpr: func(q func(string) string) string {
 			return "CAST(COALESCE(" + q("ended_at") +
 				", (SELECT MAX(m.timestamp) FROM messages m" +
 				" WHERE m.session_id = " + outerSessionID(q) +
 				" AND m.timestamp IS NOT NULL), " + q("started_at") +
-				", " + q("created_at") + ") AS DATE)"
+				", " + q("created_at") + ") AS TIMESTAMP)"
 		},
 		dateParam: func(ph string) string {
-			return "CAST(" + ph + " AS DATE)"
+			return "CAST(" + ph + " AS TIMESTAMP)"
 		},
-		activityExpr:       "COALESCE(ended_at, started_at, created_at)",
 		activityParam:      func(ph string) string { return "CAST(" + ph + " AS TIMESTAMP)" },
 		cursorActivityExpr: "COALESCE(ended_at, started_at, created_at)",
 		cursorParam: func(ph string) string {
@@ -210,6 +207,50 @@ func (d QueryDialect) Qualify(parts ...string) string {
 
 var safeIdentifierRE = regexp.MustCompile(`^[A-Za-z_][A-Za-z0-9_]*$`)
 
+// NormalizeSessionTimezone validates an IANA timezone name and returns the
+// canonical UTC default used when callers omit it. "Local" is intentionally
+// rejected because it depends on the server environment rather than naming a
+// browser-selected zone.
+func NormalizeSessionTimezone(name string) (string, error) {
+	name = strings.TrimSpace(name)
+	if name == "" {
+		return "UTC", nil
+	}
+	if name == "Local" {
+		return "", fmt.Errorf("invalid timezone: %s", name)
+	}
+	loc, err := time.LoadLocation(name)
+	if err != nil {
+		return "", fmt.Errorf("invalid timezone: %s", name)
+	}
+	return loc.String(), nil
+}
+
+func sessionDateBoundary(date, timezone string, nextDay bool) string {
+	name, err := NormalizeSessionTimezone(timezone)
+	if err != nil {
+		// Public HTTP and service inputs validate before reaching the store.
+		// Keep internal store callers deterministic if they violate that
+		// contract rather than making SQL construction panic.
+		name = "UTC"
+	}
+	loc, err := time.LoadLocation(name)
+	if err != nil {
+		loc = time.UTC
+	}
+	boundary, err := time.ParseInLocation(time.DateOnly, date, loc)
+	if err != nil {
+		// Dates are likewise validated at public boundaries. Returning the
+		// original value preserves the historical behavior for invalid
+		// internal filters.
+		return date
+	}
+	if nextDay {
+		boundary = boundary.AddDate(0, 0, 1)
+	}
+	return boundary.UTC().Format(time.RFC3339)
+}
+
 // QueryBuilder allocates dialect placeholders and collects bind parameters.
 type QueryBuilder struct {
 	dialect QueryDialect
@@ -554,21 +595,29 @@ func sessionFilterPredicates(
 	}
 	if f.Date != "" {
 		preds = append(preds, "("+b.dialect.dateEndExpr(q)+" >= "+
-			b.dialect.dateParam(b.Add(f.Date))+" AND "+
-			b.dialect.dateStartExpr(q)+" <= "+
-			b.dialect.dateParam(b.Add(f.Date))+")")
+			b.dialect.dateParam(b.Add(sessionDateBoundary(
+				f.Date, f.Timezone, false,
+			)))+" AND "+
+			b.dialect.dateStartExpr(q)+" < "+
+			b.dialect.dateParam(b.Add(sessionDateBoundary(
+				f.Date, f.Timezone, true,
+			)))+")")
 	}
 	if f.DateFrom != "" {
 		preds = append(preds, b.dialect.dateEndExpr(q)+" >= "+
-			b.dialect.dateParam(b.Add(f.DateFrom)))
+			b.dialect.dateParam(b.Add(sessionDateBoundary(
+				f.DateFrom, f.Timezone, false,
+			))))
 	}
 	if f.DateTo != "" {
-		preds = append(preds, b.dialect.dateStartExpr(q)+" <= "+
-			b.dialect.dateParam(b.Add(f.DateTo)))
+		preds = append(preds, b.dialect.dateStartExpr(q)+" < "+
+			b.dialect.dateParam(b.Add(sessionDateBoundary(
+				f.DateTo, f.Timezone, true,
+			))))
 	}
 	if f.ActiveSince != "" {
-		preds = append(preds, b.dialect.activityExpr+" >= "+
-			b.dialect.activityParam(b.Add(f.ActiveSince)))
+		preds = append(preds, b.dialect.dateEndExpr(q)+" >= "+
+			b.dialect.dateParam(b.Add(f.ActiveSince)))
 	}
 	if f.MinMessages > 0 {
 		preds = append(preds,