CompareValidator to compare user Input Date with Today (Current) date using C# and VB.Net in ASP.Net

Hi marouane,

In the page load event set the CompareValidator ValueToCompare property.

Check the below example.

HTML

<input id="input_date_travel_strat" runat="server" type="text" placeholder="Start trip" required="" value="12-05-2020" />
<asp:Button ID="Button1" Text="Submit" OnClick="Button_Click" runat="server" />
<br />
<asp:CompareValidator ID="CompareValidator1" runat="server" ErrorMessage="The date must be greater than today" ForeColor="Red"
    ControlToValidate="input_date_travel_strat" Operator="GreaterThan" Type="Date" Display="Dynamic" />

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    CompareValidator1.ValueToCompare = DateTime.Today.ToShortDateString();
}

protected void Button_Click(object sender, EventArgs e)
{

}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    CompareValidator1.ValueToCompare = DateTime.Today.ToShortDateString()
End Sub

Protected Sub Button_Click(ByVal sender As Object, ByVal e As EventArgs)
End Sub

Screenshot