C++ How to change Time and Date

Question

Hello everybody.
Haw can i change time and date in c++?
Thanks for answare.

Answer 1

[cannot post code in comments : ridiculous limit of 1000 characters...]

Tested on Windows 10 (1909) :

    SYSTEMTIME st;
    GetLocalTime(&st);
    st.wHour += 1;

    if (EnablePrivilege(GetCurrentProcess(), SE_SYSTEMTIME_NAME, TRUE))
    {
        BOOL bRet = SetLocalTime(&st);
        if (!bRet)
        {
            // Display code  for error message
        }
    }

Function adapted from MSDN/SDK =>

BOOL EnablePrivilege(HANDLE hprocess, LPWSTR privilege, BOOL flag)
{
    HANDLE hToken = NULL;
    LUID DebugValue;
    TOKEN_PRIVILEGES tkp;

    if (!OpenProcessToken(hprocess,
        TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY,
        &hToken))
        goto errexit;

    if (!LookupPrivilegeValue((LPWSTR)NULL,
        privilege,
        &DebugValue))
        goto errexit;

    tkp.PrivilegeCount = 1;
    tkp.Privileges[0].Luid = DebugValue;
    if (flag)
        tkp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED |
        SE_PRIVILEGE_ENABLED_BY_DEFAULT |
        SE_PRIVILEGE_USED_FOR_ACCESS;
    else
        tkp.Privileges[0].Attributes = NULL;

    AdjustTokenPrivileges(hToken,
        FALSE,
        &tkp,
        sizeof(TOKEN_PRIVILEGES),
        (PTOKEN_PRIVILEGES)NULL,
        (PDWORD)NULL);
    DWORD nError = GetLastError();
    // ERROR_NOT_ALL_ASSIGNED 1300 (0x514)

    if (nError != ERROR_SUCCESS)
        goto errexit;

    CloseHandle(hToken);
    return TRUE;

errexit:
    CloseHandle(hToken);
    return FALSE;
}

Answer 2

Already answered : C++ set local pc time