diff --git a/dbms/src/DataTypes/DataTypeDate.cpp b/dbms/src/DataTypes/DataTypeDate.cpp
index 27b31b0f3db59d566805c60fb7e3f0fc516502fc..66f23503d14752c820b9d1f41802eae3eff11f69 100644
--- a/dbms/src/DataTypes/DataTypeDate.cpp
+++ b/dbms/src/DataTypes/DataTypeDate.cpp
@@ -11,12 +11,12 @@ namespace DB
 
 void DataTypeDate::serializeText(const IColumn & column, size_t row_num, WriteBuffer & ostr) const
 {
-    writeDateText(DayNum_t(static_cast<const ColumnUInt16 &>(column).getData()[row_num]), ostr);
+    writeDateText(DayNum(static_cast<const ColumnUInt16 &>(column).getData()[row_num]), ostr);
 }
 
 static void deserializeText(IColumn & column, ReadBuffer & istr)
 {
-    DayNum_t x;
+    DayNum x;
     readDateText(x, istr);
     static_cast<ColumnUInt16 &>(column).getData().push_back(x);
 }
@@ -40,7 +40,7 @@ void DataTypeDate::serializeTextQuoted(const IColumn & column, size_t row_num, W
 
 void DataTypeDate::deserializeTextQuoted(IColumn & column, ReadBuffer & istr) const
 {
-    DayNum_t x;
+    DayNum x;
     assertChar('\'', istr);
     readDateText(x, istr);
     assertChar('\'', istr);
@@ -56,7 +56,7 @@ void DataTypeDate::serializeTextJSON(const IColumn & column, size_t row_num, Wri
 
 void DataTypeDate::deserializeTextJSON(IColumn & column, ReadBuffer & istr) const
 {
-    DayNum_t x;
+    DayNum x;
     assertChar('"', istr);
     readDateText(x, istr);
     assertChar('"', istr);
diff --git a/dbms/src/Functions/FunctionsComparison.h b/dbms/src/Functions/FunctionsComparison.h
index 229cbfe20e2c672f562b70e2a22183686dedfa58..2a1db9b19bccc2df0154f8762ef9775c0516a2f3 100644
--- a/dbms/src/Functions/FunctionsComparison.h
+++ b/dbms/src/Functions/FunctionsComparison.h
@@ -828,7 +828,7 @@ private:
 
         if (is_date)
         {
-            DayNum_t date;
+            DayNum date;
             ReadBufferFromMemory in(string_value.data, string_value.size);
             readDateText(date, in);
             if (!in.eof())
diff --git a/dbms/src/Functions/FunctionsConversion.h b/dbms/src/Functions/FunctionsConversion.h
index 5a284f4c4357f0bcb2b0a920fc88ec7c5b0ecacc..ec57304205c55e8e4f80a5ce469dc33cc537a56b 100644
--- a/dbms/src/Functions/FunctionsConversion.h
+++ b/dbms/src/Functions/FunctionsConversion.h
@@ -112,7 +112,7 @@ struct ToDateTimeImpl
 
     static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.fromDayNum(DayNum_t(d));
+        return time_zone.fromDayNum(DayNum(d));
     }
 };
 
@@ -175,7 +175,7 @@ struct FormatImpl<DataTypeDate>
 {
     static void execute(const DataTypeDate::FieldType x, WriteBuffer & wb, const DataTypeDate *, const DateLUTImpl *)
     {
-        writeDateText(DayNum_t(x), wb);
+        writeDateText(DayNum(x), wb);
     }
 };
 
@@ -307,7 +307,7 @@ template <typename DataType> void parseImpl(typename DataType::FieldType & x, Re
 
 template <> inline void parseImpl<DataTypeDate>(DataTypeDate::FieldType & x, ReadBuffer & rb, const DateLUTImpl *)
 {
-    DayNum_t tmp(0);
+    DayNum tmp(0);
     readDateText(tmp, rb);
     x = tmp;
 }
diff --git a/dbms/src/Functions/FunctionsDateTime.h b/dbms/src/Functions/FunctionsDateTime.h
index 9bf680245848ff56de4bab438563e6b4a764c741..d8e4c6d171f3c9771e669cc265083ac14909f889 100644
--- a/dbms/src/Functions/FunctionsDateTime.h
+++ b/dbms/src/Functions/FunctionsDateTime.h
@@ -133,7 +133,7 @@ struct ToMondayImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toFirstDayNumOfWeek(DayNum_t(d));
+        return time_zone.toFirstDayNumOfWeek(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -149,7 +149,7 @@ struct ToStartOfMonthImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toFirstDayNumOfMonth(DayNum_t(d));
+        return time_zone.toFirstDayNumOfMonth(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -165,7 +165,7 @@ struct ToStartOfQuarterImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toFirstDayNumOfQuarter(DayNum_t(d));
+        return time_zone.toFirstDayNumOfQuarter(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -181,7 +181,7 @@ struct ToStartOfYearImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toFirstDayNumOfYear(DayNum_t(d));
+        return time_zone.toFirstDayNumOfYear(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -281,7 +281,7 @@ struct ToYearImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toYear(DayNum_t(d));
+        return time_zone.toYear(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -297,7 +297,7 @@ struct ToQuarterImpl
     }
     static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toQuarter(DayNum_t(d));
+        return time_zone.toQuarter(DayNum(d));
     }
 
     using FactorTransform = ToStartOfYearImpl;
@@ -313,7 +313,7 @@ struct ToMonthImpl
     }
     static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toMonth(DayNum_t(d));
+        return time_zone.toMonth(DayNum(d));
     }
 
     using FactorTransform = ToStartOfYearImpl;
@@ -329,7 +329,7 @@ struct ToDayOfMonthImpl
     }
     static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toDayOfMonth(DayNum_t(d));
+        return time_zone.toDayOfMonth(DayNum(d));
     }
 
     using FactorTransform = ToStartOfMonthImpl;
@@ -345,7 +345,7 @@ struct ToDayOfWeekImpl
     }
     static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toDayOfWeek(DayNum_t(d));
+        return time_zone.toDayOfWeek(DayNum(d));
     }
 
     using FactorTransform = ToMondayImpl;
@@ -410,7 +410,7 @@ struct ToRelativeYearNumImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toYear(DayNum_t(d));
+        return time_zone.toYear(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -426,7 +426,7 @@ struct ToRelativeQuarterNumImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toRelativeQuarterNum(DayNum_t(d));
+        return time_zone.toRelativeQuarterNum(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -442,7 +442,7 @@ struct ToRelativeMonthNumImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toRelativeMonthNum(DayNum_t(d));
+        return time_zone.toRelativeMonthNum(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -458,7 +458,7 @@ struct ToRelativeWeekNumImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toRelativeWeekNum(DayNum_t(d));
+        return time_zone.toRelativeWeekNum(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -474,7 +474,7 @@ struct ToRelativeDayNumImpl
     }
     static inline UInt16 execute(UInt16 d, const DateLUTImpl &)
     {
-        return static_cast<DayNum_t>(d);
+        return static_cast<DayNum>(d);
     }
 
     using FactorTransform = ZeroTransform;
@@ -491,7 +491,7 @@ struct ToRelativeHourNumImpl
     }
     static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toRelativeHourNum(DayNum_t(d));
+        return time_zone.toRelativeHourNum(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -507,7 +507,7 @@ struct ToRelativeMinuteNumImpl
     }
     static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toRelativeMinuteNum(DayNum_t(d));
+        return time_zone.toRelativeMinuteNum(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -523,7 +523,7 @@ struct ToRelativeSecondNumImpl
     }
     static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.fromDayNum(DayNum_t(d));
+        return time_zone.fromDayNum(DayNum(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -539,7 +539,7 @@ struct ToYYYYMMImpl
     }
     static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toNumYYYYMM(static_cast<DayNum_t>(d));
+        return time_zone.toNumYYYYMM(static_cast<DayNum>(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -555,7 +555,7 @@ struct ToYYYYMMDDImpl
     }
     static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toNumYYYYMMDD(static_cast<DayNum_t>(d));
+        return time_zone.toNumYYYYMMDD(static_cast<DayNum>(d));
     }
 
     using FactorTransform = ZeroTransform;
@@ -571,7 +571,7 @@ struct ToYYYYMMDDhhmmssImpl
     }
     static inline UInt64 execute(UInt16 d, const DateLUTImpl & time_zone)
     {
-        return time_zone.toNumYYYYMMDDhhmmss(time_zone.toDate(static_cast<DayNum_t>(d)));
+        return time_zone.toNumYYYYMMDDhhmmss(time_zone.toDate(static_cast<DayNum>(d)));
     }
 
     using FactorTransform = ZeroTransform;
@@ -732,7 +732,7 @@ struct AddSecondsImpl
 
     static inline UInt32 execute(UInt16 d, Int64 delta, const DateLUTImpl & time_zone)
     {
-        return time_zone.fromDayNum(DayNum_t(d)) + delta;
+        return time_zone.fromDayNum(DayNum(d)) + delta;
     }
 };
 
@@ -747,7 +747,7 @@ struct AddMinutesImpl
 
     static inline UInt32 execute(UInt16 d, Int64 delta, const DateLUTImpl & time_zone)
     {
-        return time_zone.fromDayNum(DayNum_t(d)) + delta * 60;
+        return time_zone.fromDayNum(DayNum(d)) + delta * 60;
     }
 };
 
@@ -762,7 +762,7 @@ struct AddHoursImpl
 
     static inline UInt32 execute(UInt16 d, Int64 delta, const DateLUTImpl & time_zone)
     {
-        return time_zone.fromDayNum(DayNum_t(d)) + delta * 3600;
+        return time_zone.fromDayNum(DayNum(d)) + delta * 3600;
     }
 };
 
@@ -807,7 +807,7 @@ struct AddMonthsImpl
 
     static inline UInt16 execute(UInt16 d, Int64 delta, const DateLUTImpl & time_zone)
     {
-        return time_zone.addMonths(DayNum_t(d), delta);
+        return time_zone.addMonths(DayNum(d), delta);
     }
 };
 
@@ -822,7 +822,7 @@ struct AddYearsImpl
 
     static inline UInt16 execute(UInt16 d, Int64 delta, const DateLUTImpl & time_zone)
     {
-        return time_zone.addYears(DayNum_t(d), delta);
+        return time_zone.addYears(DayNum(d), delta);
     }
 };
 
diff --git a/dbms/src/IO/ReadHelpers.h b/dbms/src/IO/ReadHelpers.h
index 2d3b405675f51858a672f6cc3b7753873e81d35f..c6c58f248c2d399507b61e423f8cea7d92ae52e4 100644
--- a/dbms/src/IO/ReadHelpers.h
+++ b/dbms/src/IO/ReadHelpers.h
@@ -483,7 +483,7 @@ inline void readDateText(LocalDate & date, ReadBuffer & buf)
         readDateTextFallback(date, buf);
 }
 
-inline void readDateText(DayNum_t & date, ReadBuffer & buf)
+inline void readDateText(DayNum & date, ReadBuffer & buf)
 {
     LocalDate local_date;
     readDateText(local_date, buf);
diff --git a/dbms/src/IO/WriteHelpers.h b/dbms/src/IO/WriteHelpers.h
index e082cc92dea3882c111ba7c7b4608f90bef62fce..1261847fd1ceee5015d4263d4b1db4ff19d3ac99 100644
--- a/dbms/src/IO/WriteHelpers.h
+++ b/dbms/src/IO/WriteHelpers.h
@@ -537,7 +537,7 @@ inline void writeDateText(const LocalDate & date, WriteBuffer & buf)
 }
 
 template <char delimiter = '-'>
-inline void writeDateText(DayNum_t date, WriteBuffer & buf)
+inline void writeDateText(DayNum date, WriteBuffer & buf)
 {
     if (unlikely(!date))
     {
diff --git a/dbms/src/Interpreters/convertFieldToType.cpp b/dbms/src/Interpreters/convertFieldToType.cpp
index 361351b659bfd3885310369209cdf84349feccda..fff020ec29cb6dbd2dbbf6199541a444024e8dab 100644
--- a/dbms/src/Interpreters/convertFieldToType.cpp
+++ b/dbms/src/Interpreters/convertFieldToType.cpp
@@ -72,10 +72,10 @@ static Field convertNumericType(const Field & from, const IDataType & type)
 }
 
 
-DayNum_t stringToDate(const String & s)
+DayNum stringToDate(const String & s)
 {
     ReadBufferFromString in(s);
-    DayNum_t date{};
+    DayNum date{};
 
     readDateText(date, in);
     if (!in.eof())
diff --git a/dbms/src/Storages/MergeTree/MergeTreeDataMerger.cpp b/dbms/src/Storages/MergeTree/MergeTreeDataMerger.cpp
index f2d6e773be180c75fa7fa67cbbe2989989fae205..e0075b8e2d901c4ffd144f70d05746dc720bd635 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeDataMerger.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeDataMerger.cpp
@@ -93,8 +93,8 @@ void MergeTreeDataMerger::FuturePart::assign(MergeTreeData::DataPartsVector part
 
     if (parts.front()->storage.format_version < MERGE_TREE_DATA_MIN_FORMAT_VERSION_WITH_CUSTOM_PARTITIONING)
     {
-        DayNum_t min_date = DayNum_t(std::numeric_limits<UInt16>::max());
-        DayNum_t max_date = DayNum_t(std::numeric_limits<UInt16>::min());
+        DayNum min_date = DayNum(std::numeric_limits<UInt16>::max());
+        DayNum max_date = DayNum(std::numeric_limits<UInt16>::min());
         for (const auto & part : parts)
         {
             min_date = std::min(min_date, part->getMinDate());
diff --git a/dbms/src/Storages/MergeTree/MergeTreeDataPart.cpp b/dbms/src/Storages/MergeTree/MergeTreeDataPart.cpp
index 15c6c35afe721583a0599eea2e8de9b76b5f3ed4..0b86ba14edd506861c566ca8bf66e3404a131c7b 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeDataPart.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeDataPart.cpp
@@ -231,21 +231,21 @@ String MergeTreeDataPart::getNameWithPrefix() const
 }
 
 
-DayNum_t MergeTreeDataPart::getMinDate() const
+DayNum MergeTreeDataPart::getMinDate() const
 {
     if (storage.minmax_idx_date_column_pos != -1)
-        return DayNum_t(minmax_idx.min_values[storage.minmax_idx_date_column_pos].get<UInt64>());
+        return DayNum(minmax_idx.min_values[storage.minmax_idx_date_column_pos].get<UInt64>());
     else
-        return DayNum_t();
+        return DayNum();
 }
 
 
-DayNum_t MergeTreeDataPart::getMaxDate() const
+DayNum MergeTreeDataPart::getMaxDate() const
 {
     if (storage.minmax_idx_date_column_pos != -1)
-        return DayNum_t(minmax_idx.max_values[storage.minmax_idx_date_column_pos].get<UInt64>());
+        return DayNum(minmax_idx.max_values[storage.minmax_idx_date_column_pos].get<UInt64>());
     else
-        return DayNum_t();
+        return DayNum();
 }
 
 
@@ -469,8 +469,8 @@ void MergeTreeDataPart::loadPartitionAndMinMaxIndex()
 {
     if (storage.format_version < MERGE_TREE_DATA_MIN_FORMAT_VERSION_WITH_CUSTOM_PARTITIONING)
     {
-        DayNum_t min_date;
-        DayNum_t max_date;
+        DayNum min_date;
+        DayNum max_date;
         MergeTreePartInfo::parseMinMaxDatesFromPartName(name, min_date, max_date);
 
         const auto & date_lut = DateLUT::instance();
diff --git a/dbms/src/Storages/MergeTree/MergeTreeDataPart.h b/dbms/src/Storages/MergeTree/MergeTreeDataPart.h
index 4d693652e3d22feb38dd36cc603fb94f77adfe83..558c56f96e51ea91b0c5e607150b4562ad1a39ce 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeDataPart.h
+++ b/dbms/src/Storages/MergeTree/MergeTreeDataPart.h
@@ -65,8 +65,8 @@ struct MergeTreeDataPart
     bool contains(const MergeTreeDataPart & other) const { return info.contains(other.info); }
 
     /// If the partition key includes date column (a common case), these functions will return min and max values for this column.
-    DayNum_t getMinDate() const;
-    DayNum_t getMaxDate() const;
+    DayNum getMinDate() const;
+    DayNum getMaxDate() const;
 
     MergeTreeData & storage;
 
@@ -178,7 +178,7 @@ struct MergeTreeDataPart
         MinMaxIndex() = default;
 
         /// For month-based partitioning.
-        MinMaxIndex(DayNum_t min_date, DayNum_t max_date)
+        MinMaxIndex(DayNum min_date, DayNum max_date)
             : min_values(1, static_cast<UInt64>(min_date))
             , max_values(1, static_cast<UInt64>(max_date))
             , initialized(true)
diff --git a/dbms/src/Storages/MergeTree/MergeTreeDataWriter.cpp b/dbms/src/Storages/MergeTree/MergeTreeDataWriter.cpp
index 9d6d41fa9d5907618f7856f54b6fd4c59c7dd2cf..4565a4c677937513ee97cfdf93a484164090c3c2 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeDataWriter.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeDataWriter.cpp
@@ -140,13 +140,13 @@ MergeTreeData::MutableDataPartPtr MergeTreeDataWriter::writeTempPart(BlockWithPa
     String part_name;
     if (data.format_version < MERGE_TREE_DATA_MIN_FORMAT_VERSION_WITH_CUSTOM_PARTITIONING)
     {
-        DayNum_t min_date(minmax_idx.min_values[data.minmax_idx_date_column_pos].get<UInt64>());
-        DayNum_t max_date(minmax_idx.max_values[data.minmax_idx_date_column_pos].get<UInt64>());
+        DayNum min_date(minmax_idx.min_values[data.minmax_idx_date_column_pos].get<UInt64>());
+        DayNum max_date(minmax_idx.max_values[data.minmax_idx_date_column_pos].get<UInt64>());
 
         const auto & date_lut = DateLUT::instance();
 
-        DayNum_t min_month = date_lut.toFirstDayNumOfMonth(DayNum_t(min_date));
-        DayNum_t max_month = date_lut.toFirstDayNumOfMonth(DayNum_t(max_date));
+        DayNum min_month = date_lut.toFirstDayNumOfMonth(DayNum(min_date));
+        DayNum max_month = date_lut.toFirstDayNumOfMonth(DayNum(max_date));
 
         if (min_month != max_month)
             throw Exception("Logical error: part spans more than one month.");
diff --git a/dbms/src/Storages/MergeTree/MergeTreePartInfo.cpp b/dbms/src/Storages/MergeTree/MergeTreePartInfo.cpp
index 338dcf2249df590a1c032df7e7d4b63c314c546f..106c42ead4cdca01ef70547d976fbc59c5ccb5d0 100644
--- a/dbms/src/Storages/MergeTree/MergeTreePartInfo.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreePartInfo.cpp
@@ -78,7 +78,7 @@ bool MergeTreePartInfo::tryParsePartName(const String & dir_name, MergeTreePartI
 }
 
 
-void MergeTreePartInfo::parseMinMaxDatesFromPartName(const String & dir_name, DayNum_t & min_date, DayNum_t & max_date)
+void MergeTreePartInfo::parseMinMaxDatesFromPartName(const String & dir_name, DayNum & min_date, DayNum & max_date)
 {
     UInt32 min_yyyymmdd = 0;
     UInt32 max_yyyymmdd = 0;
@@ -97,8 +97,8 @@ void MergeTreePartInfo::parseMinMaxDatesFromPartName(const String & dir_name, Da
     min_date = date_lut.YYYYMMDDToDayNum(min_yyyymmdd);
     max_date = date_lut.YYYYMMDDToDayNum(max_yyyymmdd);
 
-    DayNum_t min_month = date_lut.toFirstDayNumOfMonth(min_date);
-    DayNum_t max_month = date_lut.toFirstDayNumOfMonth(max_date);
+    DayNum min_month = date_lut.toFirstDayNumOfMonth(min_date);
+    DayNum max_month = date_lut.toFirstDayNumOfMonth(max_date);
 
     if (min_month != max_month)
         throw Exception("Part name " + dir_name + " contains different months", ErrorCodes::BAD_DATA_PART_NAME);
@@ -129,7 +129,7 @@ String MergeTreePartInfo::getPartName() const
 }
 
 
-String MergeTreePartInfo::getPartNameV0(DayNum_t left_date, DayNum_t right_date) const
+String MergeTreePartInfo::getPartNameV0(DayNum left_date, DayNum right_date) const
 {
     const auto & date_lut = DateLUT::instance();
 
diff --git a/dbms/src/Storages/MergeTree/MergeTreePartInfo.h b/dbms/src/Storages/MergeTree/MergeTreePartInfo.h
index e664f697a2d2a827debc1b6bade7f3d760954bde..b276f1586eed53c9858428e6c9be1a431ad38532 100644
--- a/dbms/src/Storages/MergeTree/MergeTreePartInfo.h
+++ b/dbms/src/Storages/MergeTree/MergeTreePartInfo.h
@@ -52,7 +52,7 @@ struct MergeTreePartInfo
     }
 
     String getPartName() const;
-    String getPartNameV0(DayNum_t left_date, DayNum_t right_date) const;
+    String getPartNameV0(DayNum left_date, DayNum right_date) const;
     UInt64 getBlocksCount() const
     {
         return static_cast<UInt64>(max_block - min_block + 1);
@@ -62,7 +62,7 @@ struct MergeTreePartInfo
 
     static bool tryParsePartName(const String & dir_name, MergeTreePartInfo * part_info, MergeTreeDataFormatVersion format_version);
 
-    static void parseMinMaxDatesFromPartName(const String & part_name, DayNum_t & min_date, DayNum_t & max_date);
+    static void parseMinMaxDatesFromPartName(const String & part_name, DayNum & min_date, DayNum & max_date);
 
     static bool contains(const String & outer_part_name, const String & inner_part_name, MergeTreeDataFormatVersion format_version);
 };
diff --git a/dbms/src/Storages/MergeTree/MergeTreePartition.cpp b/dbms/src/Storages/MergeTree/MergeTreePartition.cpp
index b95916b2164f3fdd0b78e17063c985617aefa9b1..a68f01d51b57b23c117c91a3afada3a763cd7362 100644
--- a/dbms/src/Storages/MergeTree/MergeTreePartition.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreePartition.cpp
@@ -52,7 +52,7 @@ String MergeTreePartition::getID(const MergeTreeData & storage) const
                 result += '-';
 
             if (typeid_cast<const DataTypeDate *>(storage.partition_key_sample.getByPosition(i).type.get()))
-                result += toString(DateLUT::instance().toNumYYYYMMDD(DayNum_t(value[i].safeGet<UInt64>())));
+                result += toString(DateLUT::instance().toNumYYYYMMDD(DayNum(value[i].safeGet<UInt64>())));
             else
                 result += applyVisitor(to_string_visitor, value[i]);
 
diff --git a/dbms/src/Storages/StorageReplicatedMergeTree.cpp b/dbms/src/Storages/StorageReplicatedMergeTree.cpp
index 7306412062bf90bdd438951d6434426cbd1cd213..113fabdb793ae9c5fc4a34eba06144c81dfeb720 100644
--- a/dbms/src/Storages/StorageReplicatedMergeTree.cpp
+++ b/dbms/src/Storages/StorageReplicatedMergeTree.cpp
@@ -3139,8 +3139,8 @@ static String getPartNamePossiblyFake(MergeTreeDataFormatVersion format_version,
         /// The date range is all month long.
         const auto & lut = DateLUT::instance();
         time_t start_time = lut.YYYYMMDDToDate(parse<UInt32>(part_info.partition_id + "01"));
-        DayNum_t left_date = lut.toDayNum(start_time);
-        DayNum_t right_date = DayNum_t(static_cast<size_t>(left_date) + lut.daysInMonth(start_time) - 1);
+        DayNum left_date = lut.toDayNum(start_time);
+        DayNum right_date = DayNum(static_cast<size_t>(left_date) + lut.daysInMonth(start_time) - 1);
         return part_info.getPartNameV0(left_date, right_date);
     }
 
diff --git a/dbms/src/Storages/tests/part_name.cpp b/dbms/src/Storages/tests/part_name.cpp
index 9fdc39c569ab92d529bd259fb2a1e9a092a049cc..79c5578a8ca8d9753fea25fb87182888a4916612 100644
--- a/dbms/src/Storages/tests/part_name.cpp
+++ b/dbms/src/Storages/tests/part_name.cpp
@@ -5,9 +5,9 @@
 
 int main(int, char **)
 {
-    DayNum_t today = DateLUT::instance().toDayNum(time(nullptr));
+    DayNum today = DateLUT::instance().toDayNum(time(nullptr));
 
-    for (DayNum_t date = today; DayNum_t(date + 10) > today; --date)
+    for (DayNum date = today; DayNum(date + 10) > today; --date)
     {
         DB::MergeTreePartInfo part_info("partition", 0, 0, 0);
         std::string name = part_info.getPartNameV0(date, date);
diff --git a/libs/libcommon/include/common/DateLUTImpl.h b/libs/libcommon/include/common/DateLUTImpl.h
index 535c863eeb3e519d79022de2b6941124287d7868..499a9660262381572ba45d7f24b8c4dcedd28103 100644
--- a/libs/libcommon/include/common/DateLUTImpl.h
+++ b/libs/libcommon/include/common/DateLUTImpl.h
@@ -15,7 +15,7 @@
 #define DATE_LUT_YEARS (1 + DATE_LUT_MAX_YEAR - DATE_LUT_MIN_YEAR) /// Number of years in lookup table
 
 
-STRONG_TYPEDEF(UInt16, DayNum_t);
+STRONG_TYPEDEF(UInt16, DayNum);
 
 
 /** Lookup table to conversion of time to date, and to month / year / day of week / day of month and so on.
@@ -57,10 +57,10 @@ private:
     Values lut[DATE_LUT_SIZE];
 
     /// Year number after DATE_LUT_MIN_YEAR -> day num for start of year.
-    DayNum_t years_lut[DATE_LUT_YEARS];
+    DayNum years_lut[DATE_LUT_YEARS];
 
     /// Year number after DATE_LUT_MIN_YEAR * month number starting at zero -> day num for first day of month
-    DayNum_t years_months_lut[DATE_LUT_YEARS * 12];
+    DayNum years_months_lut[DATE_LUT_YEARS * 12];
 
     /// UTC offset at beginning of the Unix epoch. The same as unix timestamp of 1970-01-01 00:00:00 local time.
     time_t offset_at_start_of_epoch;
@@ -117,12 +117,12 @@ public:
         return lut[index - (lut[index].day_of_week - 1)].date;
     }
 
-    inline DayNum_t toFirstDayNumOfWeek(DayNum_t d) const
+    inline DayNum toFirstDayNumOfWeek(DayNum d) const
     {
-        return DayNum_t(d - (lut[d].day_of_week - 1));
+        return DayNum(d - (lut[d].day_of_week - 1));
     }
 
-    inline DayNum_t toFirstDayNumOfWeek(time_t t) const
+    inline DayNum toFirstDayNumOfWeek(time_t t) const
     {
         return toFirstDayNumOfWeek(toDayNum(t));
     }
@@ -134,18 +134,18 @@ public:
         return lut[index - (lut[index].day_of_month - 1)].date;
     }
 
-    inline DayNum_t toFirstDayNumOfMonth(DayNum_t d) const
+    inline DayNum toFirstDayNumOfMonth(DayNum d) const
     {
-        return DayNum_t(d - (lut[d].day_of_month - 1));
+        return DayNum(d - (lut[d].day_of_month - 1));
     }
 
-    inline DayNum_t toFirstDayNumOfMonth(time_t t) const
+    inline DayNum toFirstDayNumOfMonth(time_t t) const
     {
         return toFirstDayNumOfMonth(toDayNum(t));
     }
 
     /// Round down to start of quarter.
-    inline DayNum_t toFirstDayNumOfQuarter(DayNum_t d) const
+    inline DayNum toFirstDayNumOfQuarter(DayNum d) const
     {
         size_t index = d;
         size_t month_inside_quarter = (lut[index].month - 1) % 3;
@@ -157,10 +157,10 @@ public:
             --month_inside_quarter;
         }
 
-        return DayNum_t(index + 1);
+        return DayNum(index + 1);
     }
 
-    inline DayNum_t toFirstDayNumOfQuarter(time_t t) const
+    inline DayNum toFirstDayNumOfQuarter(time_t t) const
     {
         return toFirstDayNumOfQuarter(toDayNum(t));
     }
@@ -176,12 +176,12 @@ public:
         return lut[years_lut[lut[findIndex(t)].year - DATE_LUT_MIN_YEAR]].date;
     }
 
-    inline DayNum_t toFirstDayNumOfYear(DayNum_t d) const
+    inline DayNum toFirstDayNumOfYear(DayNum d) const
     {
         return years_lut[lut[d].year - DATE_LUT_MIN_YEAR];
     }
 
-    inline DayNum_t toFirstDayNumOfYear(time_t t) const
+    inline DayNum toFirstDayNumOfYear(time_t t) const
     {
         return toFirstDayNumOfYear(toDayNum(t));
     }
@@ -200,7 +200,7 @@ public:
         return lut[index - (lut[index].day_of_month - 1)].date;
     }
 
-    inline UInt8 daysInMonth(DayNum_t d) const
+    inline UInt8 daysInMonth(DayNum d) const
     {
         return lut[d].days_in_month;
     }
@@ -300,20 +300,20 @@ public:
       *  because the same calendar day starts/ends at different timestamps in different time zones)
       */
 
-    inline DayNum_t toDayNum(time_t t) const { return static_cast<DayNum_t>(findIndex(t)); }
-    inline time_t fromDayNum(DayNum_t d) const { return lut[d].date; }
+    inline DayNum toDayNum(time_t t) const { return static_cast<DayNum>(findIndex(t)); }
+    inline time_t fromDayNum(DayNum d) const { return lut[d].date; }
 
-    inline time_t toDate(DayNum_t d) const { return lut[d].date; }
-    inline unsigned toMonth(DayNum_t d) const { return lut[d].month; }
-    inline unsigned toQuarter(DayNum_t d) const { return (lut[d].month - 1) / 3 + 1; }
-    inline unsigned toYear(DayNum_t d) const { return lut[d].year; }
-    inline unsigned toDayOfWeek(DayNum_t d) const { return lut[d].day_of_week; }
-    inline unsigned toDayOfMonth(DayNum_t d) const { return lut[d].day_of_month; }
+    inline time_t toDate(DayNum d) const { return lut[d].date; }
+    inline unsigned toMonth(DayNum d) const { return lut[d].month; }
+    inline unsigned toQuarter(DayNum d) const { return (lut[d].month - 1) / 3 + 1; }
+    inline unsigned toYear(DayNum d) const { return lut[d].year; }
+    inline unsigned toDayOfWeek(DayNum d) const { return lut[d].day_of_week; }
+    inline unsigned toDayOfMonth(DayNum d) const { return lut[d].day_of_month; }
 
     /// Number of week from some fixed moment in the past. Week begins at monday.
     /// (round down to monday and divide DayNum by 7; we made an assumption,
     ///  that in domain of the function there was no weeks with any other number of days than 7)
-    inline unsigned toRelativeWeekNum(DayNum_t d) const
+    inline unsigned toRelativeWeekNum(DayNum d) const
     {
         /// We add 8 to avoid underflow at beginning of unix epoch.
         return (d + 8 - lut[d].day_of_week) / 7;
@@ -325,7 +325,7 @@ public:
     }
 
     /// Number of month from some fixed moment in the past (year * 12 + month)
-    inline unsigned toRelativeMonthNum(DayNum_t d) const
+    inline unsigned toRelativeMonthNum(DayNum d) const
     {
         return lut[d].year * 12 + lut[d].month;
     }
@@ -335,7 +335,7 @@ public:
         return toRelativeMonthNum(toDayNum(t));
     }
 
-    inline unsigned toRelativeQuarterNum(DayNum_t d) const
+    inline unsigned toRelativeQuarterNum(DayNum d) const
     {
         return lut[d].year * 4 + (lut[d].month - 1) / 3;
     }
@@ -356,7 +356,7 @@ public:
         return (t + 86400 - offset_at_start_of_epoch) / 3600;
     }
 
-    inline time_t toRelativeHourNum(DayNum_t d) const
+    inline time_t toRelativeHourNum(DayNum d) const
     {
         return toRelativeHourNum(lut[d].date);
     }
@@ -366,18 +366,18 @@ public:
         return t / 60;
     }
 
-    inline time_t toRelativeMinuteNum(DayNum_t d) const
+    inline time_t toRelativeMinuteNum(DayNum d) const
     {
         return toRelativeMinuteNum(lut[d].date);
     }
 
-    /// Create DayNum_t from year, month, day of month.
-    inline DayNum_t makeDayNum(UInt16 year, UInt8 month, UInt8 day_of_month) const
+    /// Create DayNum from year, month, day of month.
+    inline DayNum makeDayNum(UInt16 year, UInt8 month, UInt8 day_of_month) const
     {
         if (unlikely(year < DATE_LUT_MIN_YEAR || year > DATE_LUT_MAX_YEAR || month < 1 || month > 12 || day_of_month < 1 || day_of_month > 31))
-            return DayNum_t(0);
+            return DayNum(0);
 
-        return DayNum_t(years_months_lut[(year - DATE_LUT_MIN_YEAR) * 12 + month - 1] + day_of_month - 1);
+        return DayNum(years_months_lut[(year - DATE_LUT_MIN_YEAR) * 12 + month - 1] + day_of_month - 1);
     }
 
     inline time_t makeDate(UInt16 year, UInt8 month, UInt8 day_of_month) const
@@ -398,7 +398,7 @@ public:
         return lut[index].date + time_offset;
     }
 
-    inline const Values & getValues(DayNum_t d) const { return lut[d]; }
+    inline const Values & getValues(DayNum d) const { return lut[d]; }
     inline const Values & getValues(time_t t) const { return lut[findIndex(t)]; }
 
     inline UInt32 toNumYYYYMM(time_t t) const
@@ -407,7 +407,7 @@ public:
         return values.year * 100 + values.month;
     }
 
-    inline UInt32 toNumYYYYMM(DayNum_t d) const
+    inline UInt32 toNumYYYYMM(DayNum d) const
     {
         const Values & values = lut[d];
         return values.year * 100 + values.month;
@@ -419,7 +419,7 @@ public:
         return values.year * 10000 + values.month * 100 + values.day_of_month;
     }
 
-    inline UInt32 toNumYYYYMMDD(DayNum_t d) const
+    inline UInt32 toNumYYYYMMDD(DayNum d) const
     {
         const Values & values = lut[d];
         return values.year * 10000 + values.month * 100 + values.day_of_month;
@@ -430,7 +430,7 @@ public:
         return makeDate(num / 10000, num / 100 % 100, num % 100);
     }
 
-    inline DayNum_t YYYYMMDDToDayNum(UInt32 num) const
+    inline DayNum YYYYMMDDToDayNum(UInt32 num) const
     {
         return makeDayNum(num / 10000, num / 100 % 100, num % 100);
     }
@@ -497,7 +497,7 @@ public:
     /// Example: 31 Aug + 1 month = 30 Sep.
     inline time_t addMonths(time_t t, Int64 delta) const
     {
-        DayNum_t result_day = addMonths(toDayNum(t), delta);
+        DayNum result_day = addMonths(toDayNum(t), delta);
 
         time_t time_offset = toHour(t) * 3600 + toMinute(t) * 60 + toSecond(t);
 
@@ -507,7 +507,7 @@ public:
         return lut[result_day].date + time_offset;
     }
 
-    inline DayNum_t addMonths(DayNum_t d, Int64 delta) const
+    inline DayNum addMonths(DayNum d, Int64 delta) const
     {
         const Values & values = lut[d];
 
@@ -534,7 +534,7 @@ public:
     /// Saturation can occur if 29 Feb is mapped to non-leap year.
     inline time_t addYears(time_t t, Int64 delta) const
     {
-        DayNum_t result_day = addYears(toDayNum(t), delta);
+        DayNum result_day = addYears(toDayNum(t), delta);
 
         time_t time_offset = toHour(t) * 3600 + toMinute(t) * 60 + toSecond(t);
 
@@ -544,7 +544,7 @@ public:
         return lut[result_day].date + time_offset;
     }
 
-    inline DayNum_t addYears(DayNum_t d, Int64 delta) const
+    inline DayNum addYears(DayNum d, Int64 delta) const
     {
         const Values & values = lut[d];
 
@@ -607,7 +607,7 @@ public:
         return s;
     }
 
-    inline std::string dateToString(DayNum_t d) const
+    inline std::string dateToString(DayNum d) const
     {
         const Values & values = lut[d];
 
diff --git a/libs/libcommon/include/common/LocalDate.h b/libs/libcommon/include/common/LocalDate.h
index 8eddc6f911546f63a19762c41290f2eebf8145b3..9127ff20fee19b543b04a82d9f2b7dca8b3dfedb 100644
--- a/libs/libcommon/include/common/LocalDate.h
+++ b/libs/libcommon/include/common/LocalDate.h
@@ -62,7 +62,7 @@ public:
         init(time);
     }
 
-    LocalDate(DayNum_t day_num)
+    LocalDate(DayNum day_num)
     {
         const auto & values = DateLUT::instance().getValues(day_num);
         m_year  = values.year;
@@ -103,12 +103,12 @@ public:
         return DateLUT::instance().makeDate(m_year, m_month, m_day);
     }
 
-    DayNum_t getDayNum() const
+    DayNum getDayNum() const
     {
         return DateLUT::instance().makeDayNum(m_year, m_month, m_day);
     }
 
-    operator DayNum_t() const
+    operator DayNum() const
     {
         return getDayNum();
     }