diff --git a/src/corelib/time/qtimezoneprivate_win.cpp b/src/corelib/time/qtimezoneprivate_win.cpp
index 577c88187ea..61f5b30783e 100644
--- a/src/corelib/time/qtimezoneprivate_win.cpp
+++ b/src/corelib/time/qtimezoneprivate_win.cpp
@@ -58,7 +58,6 @@ QT_BEGIN_NAMESPACE
 */
 
 #define MAX_KEY_LENGTH 255
-#define FILETIME_UNIX_EPOCH Q_UINT64_C(116444736000000000)
 
 // MSDN home page for Time support
 // http://msdn.microsoft.com/en-us/library/windows/desktop/ms724962%28v=vs.85%29.aspx
@@ -71,11 +70,9 @@ QT_BEGIN_NAMESPACE
 static const wchar_t tzRegPath[] = LR"(SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones)";
 static const wchar_t currTzRegPath[] = LR"(SYSTEM\CurrentControlSet\Control\TimeZoneInformation)";
 
-constexpr qint64 MIN_YEAR = -292275056;
-constexpr qint64 MAX_YEAR = 292278994;
-constexpr qint64 MSECS_PER_DAY = 86400000;
-constexpr qint64 TIME_T_MAX = 2145916799;  // int maximum 2037-12-31T23:59:59 UTC
-constexpr qint64 JULIAN_DAY_FOR_EPOCH = 2440588; // result of julianDayFromDate(1970, 1, 1)
+constexpr qint64 MIN_YEAR = -292275056LL;
+constexpr qint64 MSECS_PER_DAY = 86400000LL;
+constexpr qint64 JULIAN_DAY_FOR_EPOCH = 2440588LL; // result of julianDayFromDate(1970, 1, 1)
 
 // Copied from MSDN, see above for link
 typedef struct _REG_TZI_FORMAT