How to combine search results

I'm using ES 7.1.2. I have indices of log records of customer logins, one index per day. I want to find a list of all customers who have not logged in the prior month. I know how to execute two aggregations, one which returns a unique list of all customers searching all indices, and one which returns the same thing but searching just the prior month's indices. What i need to do is take the difference between these two lists. I can easily do this in python, sending two GET requests and processing the results. But I want to do this so that I can display the result in Kibana, so I was hoping to use a painless script. I'm new to painless scripting and looking through the documentation I don't see any examples like this. Is this possible?

Hello Ruth,

I think you can do using Kibana also, create an index pattern for your daily created index, and then try to create the visualization on top of it.