MillisSinceEpoc
if (dateField1->MillisSinceEpoc() > dateField2->MillisSinceEpoc())
else if (dateField1->MillisSinceEpoc() < dateField2->MillisSinceEpoc())
if (existingDateField != NULL && existingDateField->MillisSinceEpoc() == millisSinceEpoc)