#include <windows.h>
#include <wchar.h>

#define WINDOWS_TICKS_PER_SEC 10000000
#define EPOCH_DIFFERENCE 11644473600LL

long long WindowsTicksToUnixSeconds(long long);

int wmain(void) {

    FILETIME ft = {0};
  
    GetSystemTimeAsFileTime(&ft);

    LARGE_INTEGER li = {0};    

    li.LowPart = ft.dwLowDateTime;
    li.HighPart = ft.dwHighDateTime;

    long long int hns = li.QuadPart;
    
    wprintf(L"Windows API time: %lli\n", hns);

    long long int utm = WindowsTicksToUnixSeconds(hns);

    wprintf(L"Unix time: %lli\n", utm);

    return 0;
}

long long int WindowsTicksToUnixSeconds(long long windowsTicks) {

     return (windowsTicks / WINDOWS_TICKS_PER_SEC - EPOCH_DIFFERENCE);
}