برنامه تبدیل تاریخ از میلادی به شمسی

using System;
using System.Windows.Forms;
using System.Globalization;
namespace tabdilTarikh
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void btnTabdil_Click(object sender, EventArgs e)
{
int y, m, d;
string[] list = new string[3];
list = txtM.Text.Split('/');
y = int.Parse(list[0]);
m = int.Parse(list[1]);
d = int.Parse(list[2]);
DateTime dt = new DateTime(y, m, d);
PersianCalendar p = new PersianCalendar();
y = p.GetYear(dt);
m = p.GetMonth(dt);
d = p.GetDayOfMonth(dt);
lblS.Text = y.ToString() + "/"
+ m.ToString() + "/"
+ d.ToString();
}
private void Form1_Load(object sender, EventArgs e)
{
DateTime dt = DateTime.Now;
txtM.Text = dt.Year.ToString()
+ "/"
+ dt.Month.ToString()
+ "/"
+ dt.Day.ToString();
}
}
}