add days to another day

Question

1/07/2014

here 07 is month

01 is date

my code is

textbox18 is date retrieved from database in database the date is saved like dd/MM/yyyy format.

1 2 3

DateTime addonday = Convert.ToDateTime(TextBox18.Text); addonday = addonday.AddDays(1); TextBox20.Text = addonday.ToString("dd/MM/yyyy");

my output is like this

08/01/2014 (1 is add with month ) my need is that 1 is add with the date

01/07/2014 (1 is date 7 is month ) my need is (02/07/201)

but output cum like this (08/01/2014)