Kirsten Smith (she/her)

If you go into Properties for your visualization and click on one of the Axis fields, then depending on the type of visualization you can right-click on the Columns field and select Custom Expression.  From here you can create your expression that will work with any filters you set.
 

If you can modify your data to be on two lines:
Name Longitude Latitude Location
antarctic -75.000000 -71.000000 1
chile -35.675147 -71.542969 1
Then you can use Line Connection to draw a line between the two points

Make sure you are creating the "new" grouping to apply colors based on those ranges:

There doesn't seem to be a way to change the axis label in the manner described, I would encourage you to vote for this suggestion on our Ideas Portal:
https://ideas.spotfire.com/ideas/TS-I-5417
 
That being said, a "maybe too simple" suggestion is to change the name of the column from [PR_AAI] to [Date] so that's what shows up in the visualization.  If you are getting updated data from an outside source you can add a Transformation to "Change column names" so the name change is handled each time you update the data.

It would be helpful to really clarify what you are trying to do, as there seems to be some confusion. In Spotfire there is IronPython as well as Python, and they work very differently.
If you are creating a script in a Text Area, that is IronPython, and you can only add .NET packages to that functionality.
If you are creating a Data Function, then you can use Python, and add various packages.
Please describe what you are attempting to do so that we can provide more direction.

I think you will find that this will be better accomplished in a TERR data function than using Spotfire functionality. You can read more about data functions here:
https://docs.tibco.com/pub/sfire-analyst/12.3.0/doc/html/en-US/TIB_sfire-analyst_UsersGuide/index.htm#t=df%2Fdf_how_to_use_a_predefined_data_function.htm
Here's a link to a YouTube video about creating data functions:

Link for TERR documentation:
https://docs.tibco.com/products/tibco-enterprise-runtime-for-r
I'd recommend that you start with the R package 'bizdays', as it has a lot of the functionality you are asking for:
https://cran.r-project.org/web/packages/bizdays/bizdays.pdf
Pass the selected date into the data function, then you can use the package to identify the fiscal quarter and return the desired number of days.

There is a work-intensive way to get the R2 data. If you click on 'More' under "Lines and Curves" you can export the curve fit data, then import the data back into Spotfire, and graph it. You can probably put together a script to export all of them, but you can at least get them into a format that can be graphed in Spotfire by exporting them.

There is no method of applying tags in the Web Player, but any tags created in the Analyst client and saved to the Library will be present and can be used for filtering.

Under Category Axis/Settings is "Categorical" checked? You aren't using a numerical field and renaming the options so they look like strings?