<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="MyWebFormPage.aspx.cs" Inherits="MatchingBirthdays.MyWebFormPage" %>

<%

DateTime GenererateRandomDate()
{
    Random gen = new Random();
    int year = gen.Next(1979, 2018);
    int month = gen.Next(1, 13);
    int day = DateTime.DaysInMonth(year,month);
    int Day = gen.Next(1, day);

    DateTime dt = new DateTime(year,month,Day);
    string matched = dt.ToString("dd/MM/yyyy");
    DateTime dtnew = Convert.ToDateTime(matched);
    DateMatched.Text = ("Date Matched: " + matched);
    return dt;
  }

%>

This is my HTML label:

        <asp:Label ID="DateMatched" runat="server" Text="First"></asp:Label>