Hey @RonGros, If I was going about this, I would change the data to have a parsed dayOfScreening field made from rounding the timestamp to the day. You could do that at ingest time, which is how I would do it, or you could create a scripted field. Here is an example of something similar being done.
In my opinion, with elasticsearch it is always better to think your data problems through from the ingestion side, even if it results in repeated information.