Figure 2.

In this case you will get the following error: "Cannot convert value of  parameter …" (even if every your "Culture" is set to "right" region):

Figure 3.

          This is the bug (nothing doing!). There are some ways to bypass this point. One of them is a little "to deceive" our DataSourceObject and allow to work not with DateTime, but just to parse your DateTime type (in itself!):   

protected void GridViewGeneral_RowUpdating

    (object sender, GridViewUpdateEventArgs e)

{

    e.OldValues["DateUpdate"] =

        DateTime.Parse(e.OldValues["DateUpdate"].ToString());

}

Don't ask me why, but it works (It is very similar to old joke. A little boy come to his father, programmer, and ask: "Why in the morning the Sun is in the East, and in the evening -  in the West". The father, programmer!, answer : "I do not know, but it works! Do not touch it!!! ")

          Good luck in programming !