Use dateTimePicker1.Value.Date to get the Date part of this DateTime value.
Do notice though, if you mean to parse into strings, that using
dateTimePicker1.Value.Date.ToString
will result with the "16/03/2012 10:10:10" string, while using something like
MyString = CStr(dateTimePicker1.Value.Date)
will result in MyString being "16/03/2012".