Template:Navseasoncats with decades below year/doc

This is a helper template for building navigation boxes in by-year chronology templates.

It uses the Navseasoncats, and adds a row below of links to decades

Usage
No parameters are needed.

Testing
For development purposes, the optional parameter cat may be used to test what the output would be on a given category page, e.g.

e.g. to test what the template would do on Category:1973 in Japan, use

Output:

Old usage
Until 19 August 2020, this template relied on the category title already having been parsed and split. These split components were then used to build the navbox.

As of 24 August 2020, this usage is no longer supported.