there are many ways to take date input in php.here
is a simple way to take date input as string and
extract the individual parts of the date as day,
month,year values.this values can be used for
different purposes -

to properly export website data to previous version of excel
use the following example as a proper starting.one can export to
using 'Response object + gridview' but its not efficient and have some
lackings..

getting dnn user information from dotnetnuke module is
easy.

you can get dotnetnuke user's User Credentials
and Profile data by the following way -

exporting to data in excel is a very common practice
in business website.one can use asp.net Response methods
to export to excel which is easy to do using a gridview.but
contents not appear properly like there will be white back-
ground over excel rows and this way is not efficient too.