Какво "не е"?
Ето от МСДН инфо:
----
GetTickCount
The GetTickCount function retrieves the number of milliseconds that have elapsed since the system was started. It is limited to the resolution of the system timer. To obtain the system timer resolution, use the GetSystemTimeAdjustment function.

DWORD GetTickCount(VOID);
Parameters
This function has no parameters.

Return Values
The return value is the number of milliseconds that have elapsed since the system was started.

Remarks
The elapsed time is stored as a DWORD value. Therefore, the time will wrap around to zero if the system is run continuously for 49.7 days.
----

За да "не е" 49 дена явно се ползва друга функция/начин за намиране на времето...