Metadata field to distinguish between "issue date" and "available date"

[alanorth]

For formally published outputs like Journal Articles it is common for the "issue date" to correspond with the date the item is included in a volume/issue. This date is usually displayed prominently on the publisher's website and acknowledged in the citation. For example, 10.1016/j.sciaf.2022.e01498:

Note that the issue date above is March, 2023, but I am writing this in February, 2023_. In very many cases the articles appear online before they appear in an issue. In this case, the item has been available online since December, 2022:

There is an increasing need to be able to distinguish between these, prompted especially by the recent PRMS reporting exercise. I propose that we use dcterms.available for this, which could be an optional field in repository systems. We can keep using the mandatory dcterms.issued to indicate the issue date.

[alanorth]

CGSpace and PRMS have definitely coalesced around using dcterms.available to indicate "Online Date" if it differs from the issue date.