Medium currently does not support native features for backdating stories and adding canonical links to your posts.
If you publish using our single story import, migration tool, WordPress plugin or via the API, the canonical link will be added automatically, and if the original publish date is found in the meta-data, it will be auto-backdated as well. Copying and pasting content into a new Medium post will not automatically backdate it or add canonical links to it.
If you're moving your posts to Medium and you're unable to use the methods above, you can submit a support request with us and we can process the posts for you.
To backdate posts, please send us a list of URLs in the following format (one item per line):
To add canonical links, please send us a list of URLs in the following format (one item per line):