I have set up an example sheet here to try to help visualize what I'm attempting to explain here.https://docs.google.com/spreadsheets/d/1kbdhVYz4eTmQ8A9JGUnyUM5vZfSbvImfegsrv-JeNHk/edit?usp=sharing
Essentially, I have an IMPORTRANGE function that is pulling data from a different sheet that is constantly having rows added and deleted.
I want a third column to print the value (the number of non-"" entries, indicative of the number of rows) of the IMPORTRANGE function at a particular time, and for that cell in the third column to not update to any future changes to that IMPORTRANGE function. In the document I included a 'Given Date' column, but it may not be truly necessary.
Whether the third cell would require a date entry from a user to take effect ('Given Date'), or update on its own automatically on each date (MM/DD/YYYY 17:00) nested inside an ARRAYFORMULA, does not particularly matter to me. I just don't know how to get something like this to work, or even if it's something that cannot be done automatically.