Add One Month to DateTime value using C# and VB.Net in ASP.Net

Hi v@run,

Refer below sample.

HTML

Date1 :
<asp:TextBox runat="server" ID="txtDate1" OnTextChanged="Change" AutoPostBack="true" />
<br />
Date2 :
<asp:TextBox runat="server" ID="txtDate2" />

Code

C#

protected void Change(object sender, EventArgs e)
{
    txtDate2.Text = Convert.ToDateTime(txtDate1.Text).AddMonths(1).ToString("dd/MMM/yyyy");
}

VB.Net

Protected Sub Change(ByVal sender As Object, ByVal e As EventArgs)
    txtDate2.Text = Convert.ToDateTime(txtDate1.Text).AddMonths(1).ToString("dd/MMM/yyyy")
End Sub

Screenshot