I believe I screwed up when I started using working hours. I believe things that I have made tags should have been classified as tasks and my tasks should be tags.
In this configuration, I am not able to discern how many hours overlap between given tags in analytics.
But I've been using working hours for more than a year now, the wrong way, I guess.
WorkingHours version: 2.8.2.0
OS + version: Windows 10