Retrieves the current system date and time.
int getMS()
Get the number of milliseconds that have ellapsed since a fixed point in time (e.g. system start). This function can be used to quickly calculate how much time has passed between two points. Note that a call to getMS() may return a smaller number than a previous call, if the millisecond time value has reached the maximum integer value and wrapped around zero. Implementations should check for this condition and perform an appropriate calculation.