Tim Hoffmann

Since plot_date is discouraged anyway, it’s unlikely that we’ll change behavior. I suggest we close this by better documenting, that tz is only used for [axis_date](https://matplotlib.org/stable/api/_as_gen/matplotlib.axis.Axis.axis_date.html#matplotlib.axis.Axis.axis_date), so affects the axis...

Ok, but then let’s rephrase this into a new issue using `plot` only.

> it seems we plot in whichever timezone came first. Which is reasonable. So, if I understand correctly, we don’t have an issue with pure `plot()`.

I'm fine with deprecating now. We've even already announced that we we will do this in the admonition at https://matplotlib.org/devdocs/api/_as_gen/matplotlib.axes.Axes.plot_date.html#matplotlib.axes.Axes.plot_date

This looks like an interesting topic with some performance gain and not too difficult (once we've figured out the right structure). :smile: I may embark on the topic. Some first...

@anntzer Thanks for the example. It helps to have an idea what could all be needed. This needed a special implementation for XTick. The same solution for a future TickCollection...

I see this topic is much more complex than exchanging a list of Lines for a LineCollection 😃. I'm still willing to work on this, but it's probably mid-term effort....

At what time is the call on Monday? See if I can join.

I actually think there is a way forward migrating to collections while *maintaining full backward compatibility* including the ability to style individual ticks. Here is how: 1. Define a facade...

https://github.com/matplotlib/matplotlib/issues/5665#issuecomment-875155264 Still holds