The way the script is setup, the filename is provided by the user. It's a little bit of work to append the details, but there's a much simpler way by using the commmand-line.
Let's say you want to name the file myreport and append time and hostname info, you can do the following:
myreport-"$(date +%F)-$(hostname -s)"
We're just appending the details using the date and hostname utility.