Very good and useful plugin. Thanks.
But I have noticed a very strange behaviour of it.
1. Timezone was set to "UTC +1". I installed the plugin and set the expiration period of one article. I did not log-out from site, I just checked the result on my site after 5-7 minutes and everything was fine - my test article disappeared from site and had a status "draft" as expected.
2. But then I had changed Timezone to "UTC +4" (I have a reason for it, because it is more correct). I tested the results on another article, but nothing happened even in a hour. I tried to logout, to change Timezone back, deactivate plugin, reinstall plugin (and noticed another strange thing - my plugin settings did not nulled when I installed plugin again, but I checked option to delete all plugin data in plugin settings...)
4. I uninstalled plugin. I had a backup of my database. So, I cleaned my database in PHPMyAdmin and imported my backup. I installed plugin again, set all things as at the first time... but nothing. It is very strange. After that I re-imported my database several times - but nothing again.
5. After all I set timezone to "America/Chicago". And everything works!
But it is so inconvenient...
I wrote all these with one idea - I'm trying to help you with this strange timezone bug. May be my information will be useful for you.