How to Mark Key Dates: Vertical / X-Axis Highlights

[alex_dinsmoor]

Looking to call out critical dates or date ranges? Do you want to do this on pivoted data?

Some example use cases for this include: highlighting promotion or event dates, drawing attention to specific trends / insights, or marking time intervals (e.g. highlighting the start of each week).

We can do this using table calculations:

• First, create a table calculation to obtain the height of the vertical bar you’d like to plot. In most cases this will be the maximum y-value (such that the highlighted range extends to the top of the chart).
  
• Second, create a table calculation that specifies which dates we’d like to highlight. If we have pivoted columns, we can use the pivot_index function to collapse them into a single column. For example, here is the table calculation we’d use to highlight the date range 6/7/18 to 6/11/18:
  

Now we have all the components to create our visualization:

• Hide the intermediate table calculation from the visualization
  
  
• Select a mixed chart type: line for data you’d like to plot, column for the date marker