My dear friend you can try this and send me feedbacks:
string day=System.DateTime.Now.Day;
string month=System.DateTime.Now.Month;
string Year=System.DateTime.Now.Year;
string hour=System.DateTime.Now.Hour;
string second=System.DateTime.Now.Second;
string minute=System.DateTime.Now.Minute;
Then you can play with them!:
string myTime=String.Format("{0}-{1}-{2}:{3}:{4}:{5}",year,month,day,hour,minute,second);
Another Example:
DateTime dat = new DateTime(2012, 1, 17, 9, 30, 0);
string city = "Chicago";
int temp = -16;
string output = String.Format("At {0} in {1}, the temperature was {2} degrees.",
dat, city, temp);
Console.WriteLine(output);
The result would be in myTime as you wish.
Good lock!