Building a UNIX Time to Date Custom Control in C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace ControlTest
{
    public partial class Form1 : Form
    {

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.Dispose();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            // use negative numbers to express dates
            // prior to 1/1/1970

            // load with unix time
            utConverter1.Text = "-885772800";  // a date prior to 1/1/1970
            utConverter2.Text = "849312000";
            utConverter3.Text = "999648000";
            utConverter4.Text = "4000000000";

            // load with normal dates
            utConverter5.Text = "7/19/1960";
            utConverter6.Text = "5/16/1933";
            utConverter7.Text = "7/4/2008";
            utConverter8.Text = "6/18/3100";

            // refresh all of the controls
            // to update the display
            utConverter1.Refresh();
            utConverter2.Refresh();
            utConverter3.Refresh();
            utConverter4.Refresh();
            utConverter5.Refresh();
            utConverter6.Refresh();
            utConverter7.Refresh();
            utConverter8.Refresh();

            // move selection off custom controls
            button1.Select();

        }
    }
}