The default Custom HTML for your knowledge base's footer will set the Copyright to: Copyright (c) 2015 - 2016. While you can manually edit the ending year, that can be a bit of a pain to remember to update. Here's a quick custom HTML change you can add to make it so you never have to update your copyright year again.
Go to Settings > Style.
Click to look at Custom HTML and make sure you're looking at the Body. You should see something like this:
Now replace the "2016" (or whatever closing year is there) with this code:
Your final custom HTML should look something like this:
Your copyright end year will now update to the current year automatically.
If you want to use this in places other than your footer, you can also create a snippet, tuck this into that snippet, and reference the snippet mergeCode here and everywhere else you want to use it!