diff --git a/3party/opening_hours/opening_hours.cpp b/3party/opening_hours/opening_hours.cpp
index cac81f87d8..441cc6a776 100644
--- a/3party/opening_hours/opening_hours.cpp
+++ b/3party/opening_hours/opening_hours.cpp
@@ -277,6 +277,16 @@ std::ostream & operator<<(std::ostream & ost, Time const & time)
   return ost;
 }
 
+bool operator==(Time const & lhs, Time const & rhs)
+{
+  if (lhs.IsEmpty() && rhs.IsEmpty())
+    return true;
+
+  return lhs.GetType() == rhs.GetType() &&
+         lhs.GetHours() == rhs.GetHours() &&
+         lhs.GetMinutes() == rhs.GetMinutes();
+}
+
 // TimespanPeriod ----------------------------------------------------------------------------------
 TimespanPeriod::TimespanPeriod(HourMinutes const & hm):
     m_hourMinutes(hm),
@@ -301,6 +311,16 @@ std::ostream & operator<<(std::ostream & ost, TimespanPeriod const p)
   return ost;
 }
 
+bool operator==(TimespanPeriod const & lhs, TimespanPeriod const & rhs)
+{
+  if (lhs.IsEmpty() && rhs.IsEmpty())
+    return true;
+
+  return lhs.GetType() == rhs.GetType() &&
+         lhs.GetHourMinutes() == rhs.GetHourMinutes() &&
+         lhs.GetMinutes() == rhs.GetMinutes();
+}
+
 // Timespan ----------------------------------------------------------------------------------------
 bool Timespan::HasExtendedHours() const
 {
@@ -349,6 +369,25 @@ std::ostream & operator<<(std::ostream & ost, osmoh::TTimespans const & timespan
   return ost;
 }
 
+bool operator==(Timespan const & lhs, Timespan const & rhs)
+{
+  if (lhs.IsEmpty() && rhs.IsEmpty())
+    return true;
+
+  if (lhs.IsEmpty() != rhs.IsEmpty() ||
+      lhs.HasStart() != rhs.HasStart() ||
+      lhs.HasEnd() != rhs.HasEnd() ||
+      lhs.HasPlus() != rhs.HasPlus() ||
+      lhs.HasPeriod() != rhs.HasPeriod())
+  {
+    return false;
+  }
+
+  return lhs.GetStart() == rhs.GetStart() &&
+         lhs.GetEnd() == rhs.GetEnd() &&
+         lhs.GetPeriod() == lhs.GetPeriod();
+}
+
 // NthWeekdayOfTheMonthEntry -----------------------------------------------------------------------
 std::ostream & operator<<(std::ostream & ost, NthWeekdayOfTheMonthEntry const entry)
 {
diff --git a/3party/opening_hours/opening_hours.hpp b/3party/opening_hours/opening_hours.hpp
index df4b9c5a9b..faf3119121 100644
--- a/3party/opening_hours/opening_hours.hpp
+++ b/3party/opening_hours/opening_hours.hpp
@@ -30,9 +30,11 @@
 #include <type_traits>
 #include <vector>
 
+// Implemented in accordance with the specification
+// http://wiki.openstreetmap.org/wiki/Key:opening_hours/specification
+
 namespace osmoh
 {
-
 class HourMinutes
 {
 public:
@@ -170,6 +172,7 @@ inline constexpr Time::TMinutes operator ""_min(unsigned long long int m)
 }
 
 std::ostream & operator<<(std::ostream & ost, Time const & time);
+bool operator==(Time const & lhs, Time const & rhs);
 
 class TimespanPeriod
 {
@@ -189,6 +192,8 @@ public:
   bool IsHoursMinutes() const { return m_type == Type::HourMinutes; }
   bool IsMinutes() const { return m_type == Type::Minutes; }
 
+  Type GetType() const { return m_type; }
+
   HourMinutes const & GetHourMinutes() const { return m_hourMinutes; }
   HourMinutes::TMinutes GetMinutes() const { return m_minutes; }
   HourMinutes::TMinutes::rep GetMinutesCount() const { return GetMinutes().count(); }
@@ -201,6 +206,7 @@ private:
 };
 
 std::ostream & operator<<(std::ostream & ost, TimespanPeriod const p);
+bool operator==(TimespanPeriod const & lhs, TimespanPeriod const & rhs);
 
 class Timespan
 {
@@ -244,6 +250,7 @@ using TTimespans = std::vector<Timespan>;
 
 std::ostream & operator<<(std::ostream & ost, Timespan const & span);
 std::ostream & operator<<(std::ostream & ost, osmoh::TTimespans const & timespans);
+bool operator==(Timespan const & lhs, Timespan const & rhs);
 
 class NthWeekdayOfTheMonthEntry
 {
diff --git a/3party/opening_hours/opening_hours_tests/opening_hours_tests.cpp b/3party/opening_hours/opening_hours_tests/opening_hours_tests.cpp
index d59b7ba6a9..a1ac06ab5c 100644
--- a/3party/opening_hours/opening_hours_tests/opening_hours_tests.cpp
+++ b/3party/opening_hours/opening_hours_tests/opening_hours_tests.cpp
@@ -1074,6 +1074,12 @@ BOOST_AUTO_TEST_CASE(OpeningHoursRuleSequence_TestParseUnparse)
   {
     auto const rule = "Sa; Su";
 
+    auto const parsedUnparsed = ParseAndUnparse<osmoh::TRuleSequences>(rule);
+    BOOST_CHECK_EQUAL(parsedUnparsed, rule);
+  }
+  {
+    auto const rule = "Sa-Su 00:00-24:00";
+
     auto const parsedUnparsed = ParseAndUnparse<osmoh::TRuleSequences>(rule);
     BOOST_CHECK_EQUAL(parsedUnparsed, rule);
   }
@@ -1426,6 +1432,46 @@ BOOST_AUTO_TEST_CASE(OpeningHours_TestIsActive)
     BOOST_CHECK(GetTimeTuple("2015-11-11 06:01", kDateTimeFmt, time));
     BOOST_CHECK(!IsActive(rules[0], time));
   }
+  {
+    TRuleSequences rules;
+    BOOST_CHECK(Parse("Mo-We 00:00-24:00", rules));
+
+    std::tm time{};
+    BOOST_CHECK(GetTimeTuple("2016-10-03 05:35", kDateTimeFmt, time));
+    BOOST_CHECK(IsActive(rules[0], time));
+
+    BOOST_CHECK(GetTimeTuple("2017-01-17 15:35", kDateTimeFmt, time));
+    BOOST_CHECK(IsActive(rules[0], time));
+
+    BOOST_CHECK(GetTimeTuple("2017-05-31 23:35", kDateTimeFmt, time));
+    BOOST_CHECK(IsActive(rules[0], time));
+
+    BOOST_CHECK(GetTimeTuple("2017-02-10 05:35", kDateTimeFmt, time));
+    BOOST_CHECK(!IsActive(rules[0], time));
+
+    BOOST_CHECK(GetTimeTuple("2017-05-21 06:01", kDateTimeFmt, time));
+    BOOST_CHECK(!IsActive(rules[0], time));
+  }
+  {
+    TRuleSequences rules;
+    BOOST_CHECK(Parse("Mo-We 00:00-24:00 off", rules));
+
+    std::tm time{};
+    BOOST_CHECK(GetTimeTuple("2016-10-03 05:35", kDateTimeFmt, time));
+    BOOST_CHECK(IsActive(rules[0], time));
+
+    BOOST_CHECK(GetTimeTuple("2017-01-17 15:35", kDateTimeFmt, time));
+    BOOST_CHECK(IsActive(rules[0], time));
+
+    BOOST_CHECK(GetTimeTuple("2017-05-31 23:35", kDateTimeFmt, time));
+    BOOST_CHECK(IsActive(rules[0], time));
+
+    BOOST_CHECK(GetTimeTuple("2017-02-10 05:35", kDateTimeFmt, time));
+    BOOST_CHECK(!IsActive(rules[0], time));
+
+    BOOST_CHECK(GetTimeTuple("2017-05-21 06:01", kDateTimeFmt, time));
+    BOOST_CHECK(!IsActive(rules[0], time));
+  }
 }
 
 BOOST_AUTO_TEST_CASE(OpeningHours_TestIsOpen)
@@ -1541,6 +1587,26 @@ BOOST_AUTO_TEST_CASE(OpeningHours_TestIsOpen)
     BOOST_CHECK(IsOpen(rules, "2016-06-05 13:06"));
     BOOST_CHECK(IsOpen(rules, "2016-05-31 18:28"));
   }
+  {
+    TRuleSequences rules;
+    BOOST_CHECK(Parse("Mo-We 00:00-24:00", rules));
+
+    BOOST_CHECK(IsOpen(rules, "2016-10-03 05:35"));
+    BOOST_CHECK(IsOpen(rules, "2017-01-17 15:35"));
+    BOOST_CHECK(IsOpen(rules, "2017-05-31 23:35"));
+    BOOST_CHECK(!IsOpen(rules, "2017-02-10 05:35"));
+    BOOST_CHECK(!IsOpen(rules, "2017-05-21 06:01"));
+  } 
+  {
+    TRuleSequences rules;
+    BOOST_CHECK(Parse("Mo-Su 00:00-24:00; Mo-We 00:00-24:00 off", rules));
+
+    BOOST_CHECK(!IsOpen(rules, "2016-10-03 05:35"));
+    BOOST_CHECK(!IsOpen(rules, "2017-01-17 15:35"));
+    BOOST_CHECK(!IsOpen(rules, "2017-05-31 23:35"));
+    BOOST_CHECK(IsOpen(rules, "2017-02-10 05:35"));
+    BOOST_CHECK(IsOpen(rules, "2017-05-21 06:01"));
+  }
 }
 
 
diff --git a/editor/ui2oh.cpp b/editor/ui2oh.cpp
index 592a686d53..2121936501 100644
--- a/editor/ui2oh.cpp
+++ b/editor/ui2oh.cpp
@@ -10,6 +10,10 @@
 
 namespace
 {
+using osmoh::operator ""_h;
+
+osmoh::Timespan const kTwentyFourHours = {0_h, 24_h};
+
 editor::ui::TOpeningDays MakeOpeningDays(osmoh::Weekdays const & wds)
 {
   set<osmoh::Weekday> openingDays;
@@ -146,9 +150,8 @@ osmoh::Weekdays MakeWeekdays(editor::ui::TimeTable const & tt)
 
 osmoh::TTimespans MakeTimespans(editor::ui::TimeTable const & tt)
 {
-
   if (tt.IsTwentyFourHours())
-    return {};
+    return {kTwentyFourHours};
 
   auto const & excludeTime = tt.GetExcludeTime();
   if (excludeTime.empty())
@@ -212,13 +215,12 @@ bool ExcludeRulePart(osmoh::RuleSequence const & rulePart, editor::ui::TimeTable
 
     auto const twentyFourHoursGuard = [](editor::ui::TimeTable & tt)
     {
-      using osmoh::operator ""_h;
       if (tt.IsTwentyFourHours())
       {
         tt.SetTwentyFourHours(false);
         // TODO(mgsergio): Consider TimeTable refactoring:
         // get rid of separation of TwentyFourHours and OpeningTime.
-        tt.SetOpeningTime({0_h, 24_h});
+        tt.SetOpeningTime(kTwentyFourHours);
       }
     };
 
@@ -350,14 +352,19 @@ bool MakeTimeTableSet(osmoh::OpeningHours const & oh, ui::TimeTableSet & tts)
     else
       tt.SetOpeningDays(kWholeWeek);
 
-    if (rulePart.HasTimes())
+    auto const & times = rulePart.GetTimes();
+
+    bool isTwentyFourHours =
+        times.empty() || (times.size() == 1 && times.front() == kTwentyFourHours);
+
+    if (isTwentyFourHours)
     {
-      tt.SetTwentyFourHours(false);
-      SetUpTimeTable(rulePart.GetTimes(), tt);
+      tt.SetTwentyFourHours(true);
     }
     else
     {
-      tt.SetTwentyFourHours(true);
+      tt.SetTwentyFourHours(false);
+      SetUpTimeTable(rulePart.GetTimes(), tt);
     }
 
     // Check size as well since ExcludeRulePart can add new time tables.