Validate jQuery Datepicker date in dd/MM/yyyy format in ASP.Net using C# and VB.Net

Hi Tevin,

Refer below code.

HTML

<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.24/themes/smoothness/jquery-ui.css" />
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.24/jquery-ui.min.js"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/json2/20160511/json2.min.js"></script>
<script type="text/javascript">
    $(document).ready(function () {
        $('#<%=txtFromDate.ClientID%>').datepicker({
            dateFormat: 'dd/mm/yy'
        });
        $('#<%=txtToDate.ClientID%>').datepicker({
            dateFormat: 'dd/mm/yy'
        });
    });
</script>
From:
<asp:TextBox ID="txtFromDate" runat="server" />
<asp:Label ID="lblFrom" Text="Enter only dd/MM/yyyy format." runat="server" Visible="false" ForeColor="Red" />
<br />
To:
<asp:TextBox ID="txtToDate" runat="server" />
<asp:Label ID="lblTo" Text="Enter only dd/MM/yyyy format." runat="server" Visible="false" ForeColor="Red" />
<br />
<asp:Button Text="Submit" runat="server" OnClick="OnSubmit" />

Code

C#

protected void OnSubmit(object sender, EventArgs e)
{
    lblFrom.Visible = false;
    lblTo.Visible = false;
    DateTime dtpFromDate;
    DateTime dtpToDate;
    if (!DateTime.TryParseExact(txtFromDate.Text.Trim(), "dd/MM/yyyy",
        System.Globalization.CultureInfo.CurrentCulture, System.Globalization.DateTimeStyles.None, out dtpFromDate))
    {
        lblFrom.Visible = true;
        ClientScript.RegisterStartupScript(this.GetType(), "alertFrom", "alert('Invalid From Date.');", true);
    }
    else
    {
        dtpFromDate = DateTime.ParseExact(txtFromDate.Text.Trim(), "dd/MM/yyyy", System.Globalization.CultureInfo.CurrentCulture);
    }

    if (!DateTime.TryParseExact(txtToDate.Text.Trim(), "dd/MM/yyyy",
        System.Globalization.CultureInfo.CurrentCulture, System.Globalization.DateTimeStyles.None, out dtpToDate))
    {
        lblTo.Visible = true;
        ClientScript.RegisterStartupScript(this.GetType(), "alertTo", "alert('Invalid To Date.');", true);
    }
    else
    {
        dtpToDate = DateTime.ParseExact(txtToDate.Text.Trim(), "dd/MM/yyyy", System.Globalization.CultureInfo.CurrentCulture);
    }
}

VB.Net

Protected Sub OnSubmit(ByVal sender As Object, ByVal e As EventArgs)
    lblFrom.Visible = False
    lblTo.Visible = False
    Dim dtpFromDate As DateTime
    Dim dtpToDate As DateTime
    If Not DateTime.TryParseExact(txtFromDate.Text.Trim(), "dd/MM/yyyy",
                                    Globalization.CultureInfo.CurrentCulture, Globalization.DateTimeStyles.None, dtpFromDate) Then
        lblFrom.Visible = True
        ClientScript.RegisterStartupScript(Me.GetType(), "alertFrom", "alert('Invalid From Date.');", True)
    Else
        dtpFromDate = DateTime.ParseExact(txtFromDate.Text.Trim(), "dd/MM/yyyy", Globalization.CultureInfo.CurrentCulture)
    End If

    If Not DateTime.TryParseExact(txtToDate.Text.Trim(), "dd/MM/yyyy",
                                    Globalization.CultureInfo.CurrentCulture, Globalization.DateTimeStyles.None, dtpToDate) Then
        lblTo.Visible = True
        ClientScript.RegisterStartupScript(Me.GetType(), "alertTo", "alert('Invalid To Date.');", True)
    Else
        dtpToDate = DateTime.ParseExact(txtToDate.Text.Trim(), "dd/MM/yyyy", Globalization.CultureInfo.CurrentCulture)
    End If
End Sub

Screenshot