Using CVIAbsoluteTimeFromFILETIME() keeps everything UTC and avoids offsets due to timezone and daylight savings
CVIAbsoluteTime now, epoch;
CVITimeInterval difference;
double TimeFromEpoch;
FILETIME fileTimeEpoc;
const long long ll = 116444736000000000;
fileTimeEpoc.dwLowDateTime = (DWORD)ll;
fileTimeEpoc.dwHighDateTime = ll >> 32;
CVIAbsoluteTimeFromFILETIME (fileTimeEpoc, &epoch);
GetCurrentCVIAbsoluteTime (&now);
SubtractCVIAbsoluteTimes (now, epoch, &difference);
CVITimeIntervalToSeconds (difference, &TimeFromEpoch);
