diff --git a/src/corelib/time/qdatetime_p.h b/src/corelib/time/qdatetime_p.h
index 5ac65bc1a5..de4de85d8c 100644
--- a/src/corelib/time/qdatetime_p.h
+++ b/src/corelib/time/qdatetime_p.h
@@ -26,6 +26,8 @@
 #include "qtimezone.h"
 #endif
 
+#include <chrono>
+
 QT_BEGIN_NAMESPACE
 
 class QDateTimePrivate : public QSharedData
@@ -113,13 +115,14 @@ Q_DECLARE_OPERATORS_FOR_FLAGS(QDateTimePrivate::StatusFlags)
 
 namespace QtPrivate {
 namespace DateTimeConstants {
-constexpr qint64 MINS_PER_HOUR = 60;
+using namespace std::chrono;
+constexpr qint64 SECS_PER_MIN = minutes::period::num;
+constexpr qint64 SECS_PER_HOUR = hours::period::num;
+constexpr qint64 SECS_PER_DAY = SECS_PER_HOUR * 24; // std::chrono::days is C++20
 
-constexpr qint64 SECS_PER_MIN = 60;
-constexpr qint64 SECS_PER_HOUR = SECS_PER_MIN * MINS_PER_HOUR;
-constexpr qint64 SECS_PER_DAY = SECS_PER_HOUR * 24;
+constexpr qint64 MINS_PER_HOUR = std::ratio_divide<hours::period, minutes::period>::num;
 
-constexpr qint64 MSECS_PER_SEC = 1000;
+constexpr qint64 MSECS_PER_SEC = milliseconds::period::den;
 constexpr qint64 MSECS_PER_MIN = SECS_PER_MIN * MSECS_PER_SEC;
 constexpr qint64 MSECS_PER_HOUR = SECS_PER_HOUR * MSECS_PER_SEC;
 constexpr qint64 MSECS_PER_DAY = SECS_PER_DAY * MSECS_PER_SEC;