Admin Forum:Chat ban options

Is there any way, how to customize time periods for chat ban expiry? I mean something like MediaWiki:Ipboptions, but for the chat. When kick isn't enough, most of our spammers on the chat usually calm down after the banning for 15-30 minutes, so I would like to enable time periods shorter that 2 hours. -- 22:16, August 27, 2012 (UTC)