How can I use VBA to turn my Excel application into a time-limited demonstration?

I have wrote a excell work book which he wants a demo

How can i give them it for a week to test out with some vba code in it to do this?


1.....I can put a time limit in to say for 1 day 1 week 1 month wich ever.

2.....vba code to stop them putting the clock back to access the work book

3.....The problem would come up if he wanted the workbook but no restriction in it IE time, also he has put in the
workbook a load of data in it.

3......He would want to keep the data that he put in

4......can a vba code be like this?
Your time is up for the demo , we have saved your data to a file but the workbook will not run now

5......He would send the workbook back to me to alter BUT how would I get in it to take out the time limit vba

6......I could then give it back to him

7......I have seen some where you can make it just run on one computer only henc not to send it anyone


SORRY for such a long ask


Thank you