Possible Clues:

• Texas clock setting, in the spring
• Midwest farmers work later on it: Abbr.
• Miss. May hours
• Chicago setting: Abbr.
• Chi. summer hours
• The Chi. Cubs play games on this
• What the Cubs play games in: Abbr.
• Aug. setting in K.C.
• Aug. time at O'Hare
• Setting for many Card games