I was trying to add a date range (not just one date or one year, but a range, like 06/15/2020 to 06/20/2020). I read in a previous post of the discussion forum that this might be feasible using the field "extra" but I cannot seem to make it work. Thanks for your help.
You can also use the CSL Visual Editor: http://editor.citationstyles.org/about/
What are you adding to the style using Extra?
For this case, enter the date in extra like this:
Issued: 2012-06-12/2013-05-21
With the keyword “issued”, the beginning and end dates in ISO format, and separated by “/“