Got this update from CME:

Quoting 

CME Globex Equity Index Trading Hours and Daily Price Limit Changes for Futures and Options Effective Sunday, November 18 (trade date Monday, November 19), the electronic trading hours on CME Globex for Equity Index futures and options will be expanded to the following: 17:00 Central Time (CT) through 16:15 CT, with a 15 minute market pause (Pre-open) from 15:15 CT to 15:30 CT. This expansion does not impact the current halt in trading on CME Globex from 8:15 CT to 15:30 CT in the following full size Equity Index contracts (SP, ND, MD & DD). With this change, the existing 5, 10, 20, and 30 percent daily price limits will be applied to the futures fixing price rather than the daily settlement price. The 5 percent ± price limits will be applied at 15:00 CT and will be in effect until 08:30 CT the following day.

This only seems to affect price limits and does not indicate any change to settlement procedures. If anyone else is reading this differently, let me know.

Posted a while back:

New CME Equity Index Hours as of November 18th 2012 Starting November 18, CME Globex Trading Day for Equity Index Products to End at 4:15 p.m. CT Change to CME Globex trading hours will coordinate with switch to daily price limits for U.S. Equity Index Products Settlement time will remain unchanged …

Mike