diff --git a/internal/manager/sleep_scheduler/calculations.go b/internal/manager/sleep_scheduler/calculations.go
index f0d2d238..fd2f8160 100644
--- a/internal/manager/sleep_scheduler/calculations.go
+++ b/internal/manager/sleep_scheduler/calculations.go
@@ -60,7 +60,7 @@ func calculateNextCheck(now time.Time, schedule *persistence.SleepSchedule) time
 	// calcNext returns the given time of day on "today" if that hasn't passed
 	// yet, otherwise on "tomorrow".
 	calcNext := func(tod persistence.TimeOfDay) time.Time {
-		nextCheck := tod.OnDate(now)
+		nextCheck := tod.OnDate(now).In(time.Local)
 		if nextCheck.Before(now) {
 			nextCheck = nextCheck.AddDate(0, 0, 1)
 		}
@@ -99,5 +99,6 @@ func earliestTime(timestamps []time.Time) time.Time {
 
 // endOfDay returns the next midnight at UTC.
 func endOfDay(now time.Time) time.Time {
-	return time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.UTC).AddDate(0, 0, 1)
+	startOfDay := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.Local)
+	return startOfDay.AddDate(0, 0, 1)
 }
diff --git a/internal/manager/sleep_scheduler/sleep_scheduler_test.go b/internal/manager/sleep_scheduler/sleep_scheduler_test.go
index 95872130..6dc0f44c 100644
--- a/internal/manager/sleep_scheduler/sleep_scheduler_test.go
+++ b/internal/manager/sleep_scheduler/sleep_scheduler_test.go
@@ -256,13 +256,14 @@ type TestMocks struct {
 // to the given time. Seconds and sub-seconds are set to zero.
 func (m *TestMocks) todayAt(hour, minute int) time.Time {
 	now := m.clock.Now()
-	return time.Date(now.Year(), now.Month(), now.Day(), hour, minute, 0, 0, now.Location())
+	todayAt := time.Date(now.Year(), now.Month(), now.Day(), hour, minute, 0, 0, time.Local)
+	return todayAt
 }
 
 // endOfDay returns midnight of the day after whatever the mocked clock's "now" is set to.
 func (m *TestMocks) endOfDay() time.Time {
-	now := m.clock.Now().UTC()
-	return time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location()).AddDate(0, 0, 1)
+	startOfToday := m.todayAt(0, 0)
+	return startOfToday.AddDate(0, 0, 1)
 }
 
 func testFixtures(t *testing.T) (*SleepScheduler, TestMocks, context.Context) {