I have a large database of news records and their published timestamp. I'm currently experimenting with using k-NN to classify the company's stock behavior by comparing the news to similar cases that have occurred in the past. Naturally, I don't want the model to use any news that has been published AFTER the news-in-question as that would not be a realistic approach.
I'm wondering if there's a way to implement this in RM? Currently, I filter the data into "News before 2021-05-03" and "News published on 2021-05-03" and feed the two streams to the training and unlabeled streams respectively.

As you can imagine, this is not a very efficient solution as it only gives me the performance results for one day. To get the performance results of 7 days, I'd have to adjust both filters 7 times, run the process and manually record the accuracy outcome.
I feel like there has got to be a better way to do this?
Thanks