diff --git a/Bedtime/Bedtime/ContentView.swift b/Bedtime/Bedtime/ContentView.swift
index 1819c41..6582649 100644
--- a/Bedtime/Bedtime/ContentView.swift
+++ b/Bedtime/Bedtime/ContentView.swift
@@ -45,7 +45,8 @@ struct ContentView: View {
         ViewModel.calculateSleepBank(
             sleepSessions: healthKitManager.sleepSessions,
             goalHours: userPreferences.sleepGoalHours,
-            recentDays: userPreferences.sleepBankDays
+            recentDays: userPreferences.sleepBankDays,
+            wakeTime: userPreferences.wakeTime
         )
     }
     
@@ -62,6 +63,7 @@ struct ContentView: View {
         SleepInsightsEngine.generateInsight(
             sleepSessions: healthKitManager.sleepSessions,
             goalHours: userPreferences.sleepGoalHours,
+            wakeTime: userPreferences.wakeTime,
             maxSleepHours: SleepWindow.maxSleepHours(
                 earliestBedtime: userPreferences.earliestReasonableBedtime,
                 wakeTime: userPreferences.wakeTime
diff --git a/Bedtime/Bedtime/Models/SleepInsights.swift b/Bedtime/Bedtime/Models/SleepInsights.swift
index d721814..a861564 100644
--- a/Bedtime/Bedtime/Models/SleepInsights.swift
+++ b/Bedtime/Bedtime/Models/SleepInsights.swift
@@ -32,9 +32,14 @@ enum SleepInsightsEngine {
     static func generateInsight(
         sleepSessions: [Date: [SleepSession]],
         goalHours: Double,
+        wakeTime: Date,
         maxSleepHours: Double
     ) -> SleepBankInsight? {
-        let snapshots = windowBalances(sleepSessions: sleepSessions, goalHours: goalHours)
+        let snapshots = windowBalances(
+            sleepSessions: sleepSessions,
+            goalHours: goalHours,
+            wakeTime: wakeTime
+        )
         guard snapshots.contains(where: { $0.sleepBank.averageHours != nil }) else {
             return nil
         }
@@ -71,13 +76,15 @@ enum SleepInsightsEngine {
 
     static func windowBalances(
         sleepSessions: [Date: [SleepSession]],
-        goalHours: Double
+        goalHours: Double,
+        wakeTime: Date
     ) -> [SleepWindowBalance] {
         windowRange.map { days in
             let bank = ViewModel.calculateSleepBank(
                 sleepSessions: sleepSessions,
                 goalHours: goalHours,
-                recentDays: days
+                recentDays: days,
+                wakeTime: wakeTime
             )
             return SleepWindowBalance(days: days, balance: bank.currentBalance, sleepBank: bank)
         }
diff --git a/Bedtime/Bedtime/Models/ViewModel.swift b/Bedtime/Bedtime/Models/ViewModel.swift
index 381d9e4..9cae4b4 100644
--- a/Bedtime/Bedtime/Models/ViewModel.swift
+++ b/Bedtime/Bedtime/Models/ViewModel.swift
@@ -11,10 +11,17 @@ class ViewModel {
     static func calculateSleepBank(
         sleepSessions: [Date: [SleepSession]],
         goalHours: Double,
-        recentDays: Int
+        recentDays: Int,
+        wakeTime: Date,
+        referenceDate: Date = Date()
     ) -> SleepBank {
         let calendar = Calendar.current
-        let endDate = Date()
+        let endDate = SleepWindow.effectiveSleepBankEndDate(
+            now: referenceDate,
+            wakeTime: wakeTime,
+            sleepSessions: sleepSessions,
+            calendar: calendar
+        )
         let startDate = calendar.date(byAdding: .day, value: -recentDays, to: endDate) ?? endDate
         
         // Filter sessions from the last N days
diff --git a/Bedtime/Bedtime/Utils/SleepWindow.swift b/Bedtime/Bedtime/Utils/SleepWindow.swift
index f9c6551..b3a9c89 100644
--- a/Bedtime/Bedtime/Utils/SleepWindow.swift
+++ b/Bedtime/Bedtime/Utils/SleepWindow.swift
@@ -70,4 +70,36 @@ struct SleepWindow {
         let components = calendar.dateComponents([.hour, .minute], from: date)
         return (components.hour ?? 0) * 60 + (components.minute ?? 0)
     }
+
+    /// End of the sleep-bank lookback window. Before today's wake time, if today has no
+    /// recorded sleep yet, the current calendar day is still in progress — use end of
+    /// yesterday so midnight doesn't shift the lookback window.
+    static func effectiveSleepBankEndDate(
+        now: Date = Date(),
+        wakeTime: Date,
+        sleepSessions: [Date: [SleepSession]],
+        calendar: Calendar = .current
+    ) -> Date {
+        let today = calendar.startOfDay(for: now)
+        let todayHasData = !(sleepSessions[today]?.isEmpty ?? true)
+        if todayHasData {
+            return now
+        }
+
+        let wakeComponents = calendar.dateComponents([.hour, .minute], from: wakeTime)
+        guard let todayWake = calendar.date(
+            bySettingHour: wakeComponents.hour ?? 0,
+            minute: wakeComponents.minute ?? 0,
+            second: 0,
+            of: today
+        ) else {
+            return now
+        }
+
+        if now < todayWake {
+            return calendar.date(byAdding: .second, value: -1, to: today) ?? now
+        }
+
+        return now
+    }
 }