To Get current system time in axapta by code you can use following method.
TimeInMS CurrentTime;
str timeinstr;
CurrentTime =timeNow();
//If you want to convert time in string format then you can use time2str method.
timeinstr =time2str(CurrentTime ,0,0);
//Syntax of time2str method is
time2Str( int _time, int _separator, int _timeFormat)