private ulong convertToMamaDateTime(DateTime val)
{
ulong dateTimeMsec = (ulong)((val.Ticks - 621355968000000000) / TimeSpan.TicksPerMillisecond);
ulong dateTime = 0;
int code = NativeMethods.mamaDateTime_setEpochTimeMilliseconds (ref dateTime, dateTimeMsec);
CheckResultCode(code);
return dateTime;
}