Deferring Jekyll Post Publication

Jekyll posts are automatically generated from the Markdown (or Textile) files in the _posts directory. But you can defer publication (really, deferring .html file generation into the _site directory) of particular files until a certain date or time. I think the doc on this is a little scattered, so I’ll go over what I’ve found here…

Only Properly Named _posts are Considered

In order to be published, a file…

1. Must be in the _posts directory, and
2. Must have a name of the form YYYY-MM-DD-brief-description.md (or other extensions as applicable. I’m going to ignore those from now on.) The YYYY-MM-DD specifier must be valid (i.e., numbers); 2014-01-XX-my-draft-file.md will not be published.

If it doesn’t meet those two critera, it won’t be published. Period, end of story.

Every Jekyll Post has a Date

_posts in Jekyll files can specify their “date” in one of two ways:

1. As a date entry in the YAML “front-matter” (a section of YAML data contained at the very top of the file, see Jekyll’s YAML front-matter documentation, or
2. Embedded within the file name itself, as we saw above.

Now, a post must have a valid date embedded within its name since, as we saw above, Jekyll won’t even look at a file without one. But, once it’s “decided to look,” the date (if any) in the YAML front-matter always trumps the date in the file name.

So, for example, if 2014-01-07-sales-meeting.md contains the following YAML front-matter:

title: Sales Meeting Results
date: 2014-02-23 10:30

, the date of the post is February 23rd t 10:30 AM, not January 7th.

Deferring Posts

By default, all “valid” (see “Only Properly Named _posts are Considered”, above) posts are published. If you want to prevent “future posts” from being published, then in the Jekyll installation’s _config.yml file add:

future: false

That makes the generator look at the date of each post (see “Every Jekyll Post has a Date”). Posts whose date is in the future will not be published.

To handle the time properly, I recommend also setting the timezone in _config.yml to avoid server time zone issues. For example, I have

   timezone: America/New_York in my config file.

So, you can “queue up” future posts in your _posts directory by giving them YAML front-matter dates in the future.

Not an Auto-Poster

This does not mean that, when you finally hit the date of a future post, the post will automatically appear. It only means that it will appear the next time you publish! You’ll need some other way to “tickle” Jekyll, or your Heroku build pack, or whatever, to do the publishing. I have some ways to do that that I’ll describe soon.