A 3 month rolling time condition is the basis for my search for duplicates to be eliminated from a 250,000-row Excel sheet.
We have a lot of user IDs and the dates on which they visited, however many of these visits are spread out over long periods of time (often more than a year), and many of them occur on the same day or a few days.
An example is the greatest method to illustrate what I want to do. So if they came to visit on January 1, January 1, January 3, January 8, February 4, June 5, December 1, and December 2, I would want to use the first date of January 1, June 4, and December 1.
If they came on January 1, January 2, January 3, February 8, or April 9, then on August 1 or September 1, I would like January 1 and August 8.
As a result, we want to book the initial date, then observe how frequently they return within 3 months of each visit, and if they go more than 3 months without coming back, book the first date they have after they do. After three months, they occasionally return four or five more times, and the data may cover several years.
Is there a way I can accomplish this?