I can confirm that C++ cannot be the reason, but there is a possible reason when the MT4 server has a wrong time zone. When the broker server provides the time, as with MT4, it is not taken from the PC but from the server. But you should see this in the start message of the log. The MT4 time difference is printed there. If you cannot find the problem, you can contact us under our support email and we'll check your logs.