diff --git a/src/Common/DateLUTImpl.h b/src/Common/DateLUTImpl.h
index b40b4d7c65b..551375d1f5c 100644
--- a/src/Common/DateLUTImpl.h
+++ b/src/Common/DateLUTImpl.h
@@ -10,6 +10,8 @@
 #include <type_traits>
 
 
+#define DATE_SECONDS_PER_DAY 86400 /// Number of seconds in a day, 60 * 60 * 24
+
 #define DATE_LUT_MIN_YEAR 1900 /// 1900 since majority of financial organizations consider 1900 as an initial year.
 #define DATE_LUT_MAX_YEAR 2299 /// Last supported year (complete)
 #define DATE_LUT_YEARS (1 + DATE_LUT_MAX_YEAR - DATE_LUT_MIN_YEAR) /// Number of years in lookup table
diff --git a/src/Functions/FunctionsConversion.h b/src/Functions/FunctionsConversion.h
index 2e21932d0e2..940585d6d57 100644
--- a/src/Functions/FunctionsConversion.h
+++ b/src/Functions/FunctionsConversion.h
@@ -300,7 +300,7 @@ struct ConvertImpl
                             if constexpr (std::is_same_v<ToDataType, DataTypeIPv4> && std::is_same_v<FromDataType, DataTypeUInt64>)
                                 vec_to[i] = static_cast<ToFieldType>(static_cast<IPv4::UnderlyingType>(vec_from[i]));
                             else if constexpr (std::is_same_v<Name, NameToUnixTimestamp> && (std::is_same_v<FromDataType, DataTypeDate> || std::is_same_v<FromDataType, DataTypeDate32>))
-                                vec_to[i] = static_cast<ToFieldType>(vec_from[i] * 86400);
+                                vec_to[i] = static_cast<ToFieldType>(vec_from[i] * DATE_SECONDS_PER_DAY);
                             else
                                 vec_to[i] = static_cast<ToFieldType>(vec_from[i]);
                         }