New event's tag/highlight in Table by long time range - Silent Attack

## What?

Think I have a Table with Events on Last Day. I want to set a field->true OR Highlight the Event Line when that event is New(based on a query from 30 days OR 15 days OR all messages)

## Why?

In cyber attacks uncommon events or events that occurs less or events that never happen before, that is more sophisticated attacks or silent attacks. Then with something like this I think will be really helpful.

## Your Environment

* Graylog Version: 4.0.1
* Elasticsearch Version: 79.3
* MongoDB Version: 4.2
* Operating System: FreeBSD 12.1