Selecting the right units for large timeline charts

We have very granular timebased data (Captured by the minute) for a very large timeframe (can go into years). This data needs to be depicted on a timeline chart something like this

The green shows normal functioning while the red depicts problem areas. This is depicted over time.

The red areas have some interactivity on hover, however there are certain cases where the time span is set to a year while the data being depicted is in minutes / hours. In such areas the red parts become very tiny, and difficult to hover on.

Basically if there's a problem area that lasted 2 hours, but is being plotted on a day, it works fine, however if the timeline were set to a month or year, the same data shrinks so much that it can't be interacted with or even noticed at times.

I was thinking of solving this by defining specific units based on selected timeline. For e.g. if the timeline selected is a year, we could only depict weeks. So a red chunk would depict a bad week. The values could be calculated as % of smooth function out total time available in the week.

However, I'm a little stuck figuring out what the right units would be and how many use cases can we have given users are free to choose any time range as needed.

So my question is

How does one decide the different units based on selected timeline

Is there a standard scale / table / research in this area