#ASP .NET TextBox: Set default & per page range validation

MyPage.aspx

<%@ Page Title="" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="MyPage.aspx.cs" Inherits="MyProject.Pages.MyPage" %>
<%@ Register TagPrefix="uc" TagName="StartDateRequired" Src="~/WebUserControl/StartDateRequired.ascx" %>

<asp:Content ID="Content1" ContentPlaceHolderID="HeadContent" runat="server">
</asp:Content>
<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
  <uc:StartDateRequired ID="TextBoxStartDate" runat="server" />
</asp:Content>

MyPage.aspx.cs

        protected void Page_LoadComplete(object sender, EventArgs e)
        {
            TextBoxStartDate.MaxValue = DateTime.Now.ToShortDateString();
            TextBoxStartDate.MinValue = DateTime.Now.AddMonths(-2).ToShortDateString();
        }

StartDateRequired.ascx

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="StartDateRequired.ascx.cs" Inherits="MyProject.WebUserControl.StartDateRequired" %>
<%@ Register assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" tagprefix="asp" %>

<!-- Reusable text box start date with pop up calendar -->

<asp:TextBox ID="TextBoxStartDate" runat="server"></asp:TextBox>

<asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" 
    ErrorMessage="Start Date is required." Text="*" ValidationGroup="AllValidations" 
    ControlToValidate="TextBoxStartDate" SetFocusOnError="true" 
    CssClass="failureNotification"></asp:RequiredFieldValidator>
<asp:RegularExpressionValidator ID="regexpDate" runat="server"         
    ErrorMessage="Date must in the the format [m]m/[d]d/yyyy" Text="*" ControlToValidate="TextBoxStartDate"         
    ValidationExpression="^\d{1,2}/\d{1,2}/\d{4}$" ValidationGroup="AllValidations" />
<asp:CalendarExtender ID="CalendarExtender1" TargetControlID="TextBoxStartDate" runat="server"></asp:CalendarExtender>         
<asp:RangeValidator ID="RangeValidator2" runat="server" ErrorMessage="Start Date outside permitted range." 
    ControlToValidate="TextBoxStartDate" Type="Date" ValidationGroup="AllValidations" Text="*" SetFocusOnError="True" CssClass="failureNotification">
</asp:RangeValidator> 

StartDateRequired.ascx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace MyProject.WebUserControl
{
 
    public partial class StartDateRequired : System.Web.UI.UserControl
    {
        public string StringKey
        {
            get
            {
                return TextBoxStartDate.Text;
            }
        }

        public string StringValue
        {
            get
            {
                return TextBoxStartDate.Text;
            }
        }

        protected void Page_Load(object sender, EventArgs e)
        {
            RangeValidator2.MaximumValue = DateTime.Now.ToShortDateString();
            RangeValidator2.MinimumValue = DateTime.Now.AddMonths(-1).ToShortDateString();
        }

        public string MaxValue
        {
            get { return (string)RangeValidator2.MaximumValue; }
            set
            {
                RangeValidator2.MaximumValue = value;
            }
        }

        public string MinValue
        {
            get { return (string)RangeValidator2.MinimumValue; }
            set
            {
                RangeValidator2.MinimumValue = value;
            }
        }
    }
}