inserting only date for a datetime format

Convert your text box value to date only:

string dValue = string.Format("{0:dd-MM-yyyy}",textbox1.Text);

Please also note that SQL Server by default stores time as well if the data type of the column is datetime. If you don't supply time, it will be defaulted to 00:00:00. If you change the column's data type to varchar or smalldatetime.

There are two option for doing this task

1. take varchar datatype of your table
2. take date datatype of your table

when you throw query from css than
string date=DateTime.now.tostring("here your date format like dd/MM/yyyy");

when you retrieving date from your database than

convert(date,your columnname,103)

where 103 is format of date
for more formats view

http://www.sql-server-helper.com/tips/date-formats.aspx[^]

if you don't need the time of the date field why don't you change the column data type as DATE?
then you can insert date in to column by using

Convert.ToDateTime(Textbox1.Text).Date;

If you can't change the data type of the column then you can get DATE from the DATETIME field when you read from the table.

try some thing like ...../.

Convert.ToDateTime(Textbox1.Text).Date;

Convert.ToDateTime(textbox.text).Date