Hello
I can help you to develop the layout display that you are looking to achieve, I do have over 25 years experience with FMP, going back to the first versions, which as you mentioned you used it around 20 years ago, perhaps you can remember the old days and versions from back then as well!
FMP has certainly changed over the time, most for the better. I read the details in your project info and looked at the attached picture, are you looking to have set dates across the top or dynamically generated columns?
If you would like to contact me with some additional information, we can confirm and I can create the structure for you.
Thank you
Darren