I have a datetimepicker which on loading of windows form shows me format in \'MM-dd-yyyy\',
as follows:
You could easily use:
label1.Text = dateTimePicker1.Value.Date.ToString("dd/MM/yyyy")
and if you want to change '/' or '-', just add this:
label1.Text = label1.Text.Replace(".", "-")
More info about DateTimePicker.CustomFormat Property: Link