For posts in the current year they are published without the year as the published date. Is there a setting that I am missing? I want to show the full date of the blog post.
I guess, your query is related to this feature request for Wix Blog:
https://support.wix.com/en/article/wix-blog-request-changing-the-format-of-the-date-in-a-blog-post you can vote for it, so Wix Blog developers will be able to track that you are interested in this feature.