We would like to have a new feature on Custom Dashboards: the ability to display markers on custom dashboards details, based on datetime or period.

It would help users to read the boards and visually see when a particular internal event occurred: new version on production, hotfix deployment, heavy-impact scheduled jobs, etc.

Example 1: marker with a given date and a description

Example 2: period marker with a description

The main idea is to implement something like "Milestone Markers" for custom dashboards based on Web Transaction monitors (browser-simulated user interaction)