There are several plugins available to create timeline archives, even to create series but most of them are usually lacking. Whether they try to do too much, load lots of CSS [and whatnots], are [slightly] buggy or have output which is rather horrendous.
Paul Eiche, author of the lightweight and underrated longform theme Cover 21 which supports the AESOP story engine, has suffered the same struggle finding a decent timeline and decided to write his own plugin2.
There are two kinds of timeline plugins for WordPress. The first — where you have to create a new post for every event in your timeline — is far more prevalent on the WordPress.org Plugin Directory.
The second type, the type I was looking for, allows existing posts to be modified so that they show up on a timeline. This is much rarer; in fact, I have literally only found a single plugin that fits this description
Timelines Plugin for Post Series
Upon activation, the Timelines plugin adds a metabox to the post editor with the ‘timeline thread selector’, as well as an icon selector for timeline entries.
The icon selector lets authors pick a Font Awesome icon for the entry, which is used on the timeline. Paul has built the plugin to make use of Select2, in order to avoid needing to hardocre the whole Font Awesome icon library all while offering an easier way to select an appropriate icon.
Eiche’s Timelines plugin is a neat, and rather lightweight solution, to include clean and responsive timelines to a website or blog. It is an ideal solution for series writers or for reviewers of periodicals like comics.
The plugin also displays a ‘series’/timeline meta box below the article’s content.
At the time of writing the plugin has not been submitted to the WordPress plugin directory yet, but can be downloaded at Github.
Read more about the plugin at Paul Eiche’s Timelines plugin project page, a link to the timeline for his timelines plugin posts.