The reason OPP does not change your copyright dates is because the copyright dates on your site should reflect the dates upon which the material was created.
Therefore, you should use the earliest date in which you created material for the site, as well as the latest date. If you have not posted any work from 2012 as of yet, your copyright dates will not update automatically.
If you'd like to change your copyright dates regardless of when you created the material on your site, you are definitely free to do so.
Please see our Pixelpedia Section for detailed instructions on how to change your Copyright Holder Text.
Of course, another way to get your copyright dates to change automatically would be to post new work -- so get back into that studio, and create away.