Outputs the number of days until a specified date from shortcode embedded in content.
Originally I used the "Countdown Timer" plugin written by Andrew Ferguson to accomplish what I wanted, however, his implementation to output in just days also outputted extraneous text that I was not interested in. On top of that, the actual count algorithm was flawed. Rather than hack this plugin to pieces to get the output I needed, I decided to just roll my own.
This is a bare bones, no-frills plugin since this is my first attempt at it. This means no fancy options or configuration screens.
To use the plugin, simply install it and then use the following shortcode to output the number of days until a given date in its place:
[days_until date="SPECIFIC DATE"]
Where "SPECIFIC DATE" can be any text that that PHP's strtotime function can understand.