diff --git a/App/StudyAppApp.swift b/App/StudyAppApp.swift
index 9039d7b..e85b433 100644
--- a/App/StudyAppApp.swift
+++ b/App/StudyAppApp.swift
@@ -134,26 +134,30 @@ struct StudyAppApp: App {
             BackupCommands(viewModel: backupViewModel)
         }
 
-        MenuBarExtra(isInserted: menuBarItemInserted) {
-            MenuBarContent(
-                summary: menuBarSummary,
-                onOpenLecture: { moduleID in
-                    Self.bringToFront()
-                    navigation.show(module: moduleID, section: .slides, intent: .resumeSlides)
-                },
-                onReviewCards: {
-                    Self.bringToFront()
-                    // Starts with the module that has the most due cards, like „Lernen starten“ on Today.
-                    if let moduleID = todayViewModel.dueCounts.max(by: { $0.value < $1.value })?.key {
-                        navigation.show(module: moduleID, section: .flashcards)
-                    }
-                },
-                onOpenApp: { Self.bringToFront() }
-            )
-            .tint(Theme.accent)
-            .preferredColorScheme(appearance.colorScheme)
+        MenuBarExtra(isInserted: $showsMenuBarItem) {
+            MenuBarSummaryReader(calendar: calendarViewModel, today: todayViewModel) { summary in
+                MenuBarContent(
+                    summary: summary,
+                    onOpenLecture: { moduleID in
+                        Self.bringToFront()
+                        navigation.show(module: moduleID, section: .slides, intent: .resumeSlides)
+                    },
+                    onReviewCards: {
+                        Self.bringToFront()
+                        // Starts with the module that has the most due cards, like „Lernen starten“ on Today.
+                        if let moduleID = todayViewModel.dueCounts.max(by: { $0.value < $1.value })?.key {
+                            navigation.show(module: moduleID, section: .flashcards)
+                        }
+                    },
+                    onOpenApp: { Self.bringToFront() }
+                )
+                .tint(Theme.accent)
+                .preferredColorScheme(appearance.colorScheme)
+            }
         } label: {
-            MenuBarLabel(summary: menuBarSummary)
+            MenuBarSummaryReader(calendar: calendarViewModel, today: todayViewModel) { summary in
+                MenuBarLabel(summary: summary)
+            }
         }
         .menuBarExtraStyle(.window)
 
@@ -193,23 +197,6 @@ struct StudyAppApp: App {
         await notificationsViewModel.refresh()
     }
 
-    /// Keeps the menu bar item out of the unit test host: on CI runners its status item
-    /// blocks the launch, so the test runner never connects.
-    private var menuBarItemInserted: Binding<Bool> {
-        Binding(
-            get: { showsMenuBarItem && !Self.isRunningAsTestHost },
-            set: { showsMenuBarItem = $0 }
-        )
-    }
-
-    private static var isRunningAsTestHost: Bool {
-        ProcessInfo.processInfo.environment["XCTestConfigurationFilePath"] != nil
-    }
-
-    private var menuBarSummary: MenuBarSummary {
-        MenuBarSummary(calendar: calendarViewModel, dueCards: todayViewModel.totalDue)
-    }
-
     /// Shows the main window, e.g. after a click in the menu bar.
     private static func bringToFront() {
         NSApplication.shared.activate()
diff --git a/Presentation/MenuBar/MenuBarContent.swift b/Presentation/MenuBar/MenuBarContent.swift
index 9499508..6896019 100644
--- a/Presentation/MenuBar/MenuBarContent.swift
+++ b/Presentation/MenuBar/MenuBarContent.swift
@@ -1,6 +1,18 @@
 import AppKit
 import SwiftUI
 
+/// Builds the summary inside a view, so only the menu bar item observes the calendar and the due cards.
+/// Reading them in the App body would rebuild every scene on each change, already while the app launches.
+struct MenuBarSummaryReader<Content: View>: View {
+    let calendar: StudyCalendarViewModel
+    let today: TodayViewModel
+    @ViewBuilder let content: (MenuBarSummary) -> Content
+
+    var body: some View {
+        content(MenuBarSummary(calendar: calendar, dueCards: today.totalDue))
+    }
+}
+
 /// The menu bar item's label: an icon, plus the remaining minutes while a lecture runs.
 struct MenuBarLabel: View {
     let summary: MenuBarSummary