You have to format the date string so that it can be converted into a DateTime
instance. You need to be careful that the milliseconds do not get truncated during the conversion.Something along these lines should do the trick.
string myDateAsString = "25/10/2022 10:31 787";
DateTime myDateAsDateTime = DateTime.ParseExact(myDateAsString, "dd/MM/yyyy HH:mm fff",
CultureInfo.InvariantCulture);