If your GitHub Pages repository contains a post with an invalid date, your GitHub Pages site will not build.

If your GitHub Pages site fails to build because of a post with an invalid date in the filename, you'll get an email that looks like this:

Subject: Page build failed

The page build failed with the following error:

"The post `2012-02-30-time-is-an-illusion.md` does not have a valid date in the filename."

And if your GitHub Pages site fails to build because of a post with an invalid date in the YAML front matter, you'll get an email that looks like this:

Subject: Page build failed

The page build failed with the following error:

"The post `2012-02-30-time-is-an-illusion.md` does not have a valid date in the YAML front matter."

You will only receive an email if outbound email support is enabled on your Enterprise instance. For more information, contact your site administrator.

Troubleshooting post date errors

Tip: We strongly recommend running Jekyll locally so you can easily debug and fix build errors before pushing to your GitHub Enterprise instance. To learn more about troubleshooting options, see "Troubleshooting GitHub Pages builds."

  • Make sure you're using proper date formatting for filenames with dates and any date values in the YAML front matter of your files. Dates must be formatted as YYYY-MM-DD HH:MM:SS for UTC, and must be actual calendar dates.
  • If you specify a date format in your _config.yml file, make sure you format it correctly. To specify a time zone with an offset from UTC, use the format YYYY-MM-DD HH:MM:SS +/-TTTT. For example: 2014-04-18 11:30:00 +0800.

Once you've fixed all post date errors, you will need to commit your changes and push to your GitHub Pages repository again to trigger another build on the server.