diff --git a/editor/editor_tests/opening_hours_ui_test.cpp b/editor/editor_tests/opening_hours_ui_test.cpp
index b851526ceb..f2966175f7 100644
--- a/editor/editor_tests/opening_hours_ui_test.cpp
+++ b/editor/editor_tests/opening_hours_ui_test.cpp
@@ -157,33 +157,38 @@ UNIT_TEST(TestAppendTimeTable)
 {
   {
     TimeTableSet tts;
-    TEST(!tts.empty(), ());
+    TEST(!tts.Empty(), ());
 
-    auto tt = tts.back();
+    {
+      auto tt = tts.Back();
 
-    TEST(tt.RemoveWorkingDay(osmoh::Weekday::Sunday), ());
-    TEST(tt.RemoveWorkingDay(osmoh::Weekday::Saturday), ());
-    TEST(tts.Replace(tt, 0), ());
+      TEST(tt.RemoveWorkingDay(osmoh::Weekday::Sunday), ());
+      TEST(tt.RemoveWorkingDay(osmoh::Weekday::Saturday), ());
+      TEST(tt.Commit(), ());
+
+      TEST(tts.Append(tts.GetComplementTimeTable()), ());
+      TEST_EQUAL(tts.Back().GetWorkingDays(), (set<osmoh::Weekday>{osmoh::Weekday::Sunday,
+                osmoh::Weekday::Saturday}), ());
+    }
+
+    {
+      auto tt = tts.Front();
+      TEST(tt.RemoveWorkingDay(osmoh::Weekday::Monday), ());
+      TEST(tt.RemoveWorkingDay(osmoh::Weekday::Tuesday), ());
+      TEST(tt.Commit(), ());
+    }
 
     TEST(tts.Append(tts.GetComplementTimeTable()), ());
-    TEST_EQUAL(tts.back().GetWorkingDays(), (set<osmoh::Weekday>{osmoh::Weekday::Sunday,
-              osmoh::Weekday::Saturday}), ());
-    tt = tts.front();
-    TEST(tt.RemoveWorkingDay(osmoh::Weekday::Monday), ());
-    TEST(tt.RemoveWorkingDay(osmoh::Weekday::Tuesday), ());
-    TEST(tts.Replace(tt, 0), ());
-
-    TEST(tts.Append(tts.GetComplementTimeTable()), ());
-    TEST_EQUAL(tts.back().GetWorkingDays(), (set<osmoh::Weekday>{osmoh::Weekday::Monday,
+    TEST_EQUAL(tts.Back().GetWorkingDays(), (set<osmoh::Weekday>{osmoh::Weekday::Monday,
               osmoh::Weekday::Tuesday}), ());
 
     TEST(!tts.GetComplementTimeTable().IsValid(), ());
     TEST(!tts.Append(tts.GetComplementTimeTable()), ());
-    TEST_EQUAL(tts.size(), 3, ());
+    TEST_EQUAL(tts.Size(), 3, ());
 
     TEST(!tts.Remove(0), ());
     TEST(tts.Remove(1), ());
-    TEST_EQUAL(tts.size(), 2, ());
+    TEST_EQUAL(tts.Size(), 2, ());
     TEST_EQUAL(tts.GetUnhandledDays(), (set<osmoh::Weekday>{osmoh::Weekday::Sunday,
               osmoh::Weekday::Saturday}), ());
   }
@@ -196,9 +201,9 @@ UNIT_TEST(TestAppendTimeTable)
 
     TEST(tts.Append(tt), ());
 
-    TEST_EQUAL(tts.size(), 2, ());
-    TEST_EQUAL(tts.front().GetWorkingDays().size(), 4, ());
-    TEST_EQUAL(tts.back().GetWorkingDays().size(), 3, ());
+    TEST_EQUAL(tts.Size(), 2, ());
+    TEST_EQUAL(tts.Front().GetWorkingDays().size(), 4, ());
+    TEST_EQUAL(tts.Back().GetWorkingDays().size(), 3, ());
 
     TEST(!tts.GetComplementTimeTable().IsValid(), ());
   }
@@ -209,16 +214,33 @@ UNIT_TEST(TestAppendTimeTable)
 
     TEST(tts.Append(tt), ());
 
-    TEST_EQUAL(tts.size(), 2, ());
-    TEST_EQUAL(tts.front().GetWorkingDays().size(), 6, ());
-    TEST_EQUAL(tts.back().GetWorkingDays().size(), 1, ());
+    TEST_EQUAL(tts.Size(), 2, ());
+    TEST_EQUAL(tts.Front().GetWorkingDays().size(), 6, ());
+    TEST_EQUAL(tts.Back().GetWorkingDays().size(), 1, ());
 
     TEST(!tts.GetComplementTimeTable().IsValid(), ());
 
-    tt = tts[0];
+    tt = tts.Front();
     tt.AddWorkingDay(osmoh::Weekday::Friday);
     TEST(!tts.Append(tt), ());
-    TEST_EQUAL(tts.front().GetWorkingDays().size(), 6, ());
-    TEST_EQUAL(tts.back().GetWorkingDays().size(), 1, ());
+    TEST_EQUAL(tts.Front().GetWorkingDays().size(), 6, ());
+    TEST_EQUAL(tts.Back().GetWorkingDays().size(), 1, ());
+  }
+  {
+    TimeTableSet tts;
+
+    {
+      auto tt = tts.GetComplementTimeTable();
+      tt.AddWorkingDay(osmoh::Weekday::Friday);
+      TEST(tts.Append(tt), ());
+    }
+
+    TEST_EQUAL(tts.Size(), 2, ());
+    TEST_EQUAL(tts.Front().GetWorkingDays().size(), 6, ());
+    TEST_EQUAL(tts.Back().GetWorkingDays().size(), 1, ());
+
+    auto tt = tts.Front();
+    tt.AddWorkingDay(osmoh::Weekday::Friday);
+    TEST(!tt.Commit(), ());
   }
 }
diff --git a/editor/opening_hours_ui.hpp b/editor/opening_hours_ui.hpp
index bdfb00cb7c..2dd3543b0f 100644
--- a/editor/opening_hours_ui.hpp
+++ b/editor/opening_hours_ui.hpp
@@ -47,7 +47,28 @@ private:
   osmoh::TTimespans m_excludeTime;
 };
 
-class TimeTableSet : public vector<TimeTable>
+template <typename TTimeTableSet>
+class TimeTableProxyBase : public TimeTable
+{
+public:
+  TimeTableProxyBase(TTimeTableSet & tts, size_t const index, TimeTable const & tt):
+      TimeTable(tt),
+      m_index(index),
+      m_tts(tts)
+  {
+  }
+
+  bool Commit() { return m_tts.Replace(*this, m_index); } // Slice base class on copy.
+
+private:
+  size_t const m_index;
+  TTimeTableSet & m_tts;
+};
+
+class TimeTableSet;
+using TTimeTableProxy = TimeTableProxyBase<TimeTableSet>;
+
+class TimeTableSet : vector<TimeTable>
 {
 public:
   using vector<TimeTable>::vector;
@@ -58,6 +79,13 @@ public:
 
   TimeTable GetComplementTimeTable() const;
 
+  TTimeTableProxy Get(size_t const index) { return TTimeTableProxy(*this, index, (*this)[index]); }
+  TTimeTableProxy Front() { return Get(0); }
+  TTimeTableProxy Back() { return Get(Size() - 1); }
+
+  size_t Size() const { return size(); }
+  bool Empty() const { return empty(); }
+
   bool Append(TimeTable const & tt);
   bool Remove(size_t const index);
 
@@ -65,6 +93,7 @@ public:
 
 private:
   static bool UpdateByIndex(TimeTableSet & ttSet, size_t const index);
+
 };
 } // namespace ui
 } // namespace editor