selected date want to display in datagridview using csharp

Question

Design as follows
 

Calendar (control name month calendar)
 
Note: it is windows application.
 

Run mode as follows;
In the run mode when i select any month and click, that month all dates want to display in dategridview.
 

My code as follows;
 
private void Facavailcal_DateChanged(object sender, DateRangeEventArgs e)
{

DateTime dt1 = Facavailcal.TodayDate;
dt1 = new DateTime(dt1.Year, dt1.Month, 1);
DateTime dt2 = dt1.AddMonths(1);
int numDays = (dt2 - dt1).Days;
 
if (DGVCalendar.RowCount < numDays)
{
DGVCalendar.RowCount = numDays;
}
 
int row = 0;
while (dt1 < dt2)
{
DGVCalendar.Rows[row].Cells[0].Value = dt1.ToString("dd/MM/yyyy");
dt1 = dt1.AddDays(1);
row++;
}
 
}

 
in the above code, in the run mode in the calendar february month is there,when i select the that month  all date is display in datagridview.

suppose when i select march month means, that month all  date is not display in dategridview.
 

from my above code what is the problem.

please help me.