Using dates as tags sounds like a good recipe for clutter.
I personally like to keep track of dates, but I don’t need them to be dynamically graphed by Obsidian itself. So I ended up just using them as fields in the frontmatter.
For example, the template I use for articles or technical cards I save starts with this :
---
creation date: <% tp.file.creation_date() %>
source:
author:
date:
---
The date field is the date at which the piece I’m saving was published. It helps me keep track of the point in time at which this information was relevant, as things can evolve with updates and so on.
As far as I’m concerned, dates are part of metadata unless you’re talking about notes that are the consequence of a date (like daily notes).
YAML metadata can be queried with Dataview, which I think might fit your use-case.