Date format change

Question

below in code if

f.StartDate=22/10/2019

date available this date convert in any machine format in c# 

 

DateTime dt1StartPaymentDate = DateTime.ParseExact(f.StartDate, "dd/MM/yyyy", System.Globalization.CultureInfo.InvariantCulture);
         string startdate = dt1StartPaymentDate.ToString("MM/dd/yyyy");
         string starttime = f.StartTime;
         string startdatetime = startdate + " " + starttime;
         DateTime startingtime = Convert.ToDateTime(startdatetime);