Search for Records with no new entries?

So I got a little closer...I added a summary field on the Assets Table to display True/False if there are any Related Rental Rate records related to the Asset if Compare Date? is checked and Search Date? is not checked. If I then create a filter report in the Assets table to display those Assets with a false result, it does give me a list of Assets, but the total isn't correct. This report should give me 43 Assets but it only gives me 33.

I think I might have missed something as this solution isn't working as intended.

I created a new Table Rate Filter with Record ID#, Compare Date, and Search Date. Added 1 record.

In my Rates Table, I created a Rate Filter ID (formula numeric = 1). Then I made a relationship between the Rates and Rate Filter using linking to the Rate Filter ID formula field created. I Looked up the Compare Date and Search Date files from Rate Filter. I then created 2 formula checkboxes:

[Compare Date?] (If Rate Start Date = Compare Date, then true, false)

[Search Date?] (If Rate Start Date = Search Date, then true, false)

In my Rates Table I created a new table report that filters my Rates:

If Compare Date is checked and Search Date is not checked.

What returned was a listing of all the instances where an Asset had a record for the Compare Date entry but not one for the Search Date entry. So basically over a thousand records. 

When I run a straight report from my Rates table to see how many rate entries there were for 07-01-2025 I get a total of 345. When I run it again to see how many rate entries there were for 08-01-2025 I get 302. My goal for this report is, when ran, it would show me ONLY the 43 Assets that appear in July but didn't appear in August.

I tried reversing my entries (so that the 08-01-2025 was the compare date and 07-01-2025 was the search date I get the same results.

Thanks Mark, yes I had explored your first suggestion, but as you mentioned, an Admin (or someone with higher access) would need to manually update each time this report would need to be ran (which may not be that often, but...). That way could lead to other things getting broken in the process.

I think I understand your second suggestion, confused on:

"Make a relationship back to all Rates with a reference field on the rates table of a formula numeric with a formula of 1."

I think I understand the purpose, so that each and every Rate record (now and in the future) would all relate to the single Rate Filter record. But why must it be a formula numeric reference field? Couldn't it just be a simple numeric field with a default value of 1?

In the end your solution is offering a pathway for users to use the Rate Filters form to enter the 2 dates they would like to compare, which would then display those Assets not meeting those search parameters. Lovely.

Yes. This is a Rate sheet. Rates relate to Assets (1 Asset can have many rates). I would like to see which Assets had a Rate for 07-01-2025 but don't have one for 08-01-2025. I ran a report to show Assets with Rates for 07-01-2025 and 08-01-2025, downloaded to csv, then used conditional formatting to identify duplicate Asset #'s (thus seeing which ones weren't duplicated). The report returned a total of 646 rates and of those 40 weren't duplicated, thus missing their 08-01-2025 rate.

Was just looking for an "in-system" way to replicate the same results. A way to display the 40 Asset numbers that had a rate in July but not one in August.

I am having some difficulty exactly understanding your question. Is there another field on the table like a customer name or something like that and you're trying to find out which customers have an entry on July 1 but not August 1?