Bug 48418 added the additional VCS fields that Special:Version displays into the siteinfo/extension API call. The vas-date property appears to be returning the current date instead of the correct date for the extension.
If you access
https://wikiapiary.com/w/api.php?action=query&meta=siteinfo&siprop=extensions&format=json
and note the vcs-date, they are all the same and they change with every reload.
You can also see this here
https://wikiapiary.com/w/index.php?title=WikiApiary/Extensions&diff=next&oldid=890646
and look at older edits to see the changes everytime WikiApiary updates.
Version: 1.23rc
Severity: normal