i want to convert datetime format

Convert DateTime[^]

Convert DateTime[^]

Your format in the database is not culture specific. It is the conversion to a string that is culture specific. If you change the culture, then you change the format of the DataTime. What you need to do is change the culture. If you change the culture to US, then you will always be in dd/mm/yy, for France it would be

// C#
// Put the using statements at the beginning of the code module
using System.Threading;
using System.Globalization;
// Put the following code before InitializeComponent()
// Sets the culture to French (France)
Thread.CurrentThread.CurrentCulture = new CultureInfo("fr-FR");
// Sets the UI culture to French (France)
Thread.CurrentThread.CurrentUICulture = new CultureInfo("fr-FR");

Just change to "en-US"

You have to insert in to MM/dd/yyyy formate and fetch data using dd/MM/yyyy format.

cmd = New SqlCommand("insert into test values( '" & Format(CType(DTPDT.Text, Date), "MM/dd/yyyy") & "'  )", con)
       cmd.ExecuteNonQuery()

for view in dd/MM/yyyy format.

Format(CType(DateTimePicker1.Text, Date), "dd/MM/yyyy")

You cant change default date set in database.You have to change the format of date while inserting and retrieving.

here is the one way to do this.

this.datetimepicker1.customformat="MM/dd/yyyy";
this.datetimepicker1.format=datetimepicker.format;
_defaultDate=datetimepicker1.text;
this.datetimepicker1.customformat="dd/MM/yyyy";
this.datetimepicker1.format=datetimepicker.format;

hope this helps you..