If you read the rules, this is what they say...
C. Duration of Program
1. The current phase of the Program begins at 12:00 a.m. Eastern Time ("ET") on January 1, 2011 and is scheduled to end at 11:59 p.m. ET on December 31, 2011 (the "Redemption Period"), but Sponsor reserves the right to shorten, extend, suspend, modify, or cancel the Program, at its discretion, at any time. Codes may be entered beginning 12:00 a.m. ET on January 1, 2011 until 11:59 p.m. ET on November 30, 2011 (the "Collection Period"), and participants will be able to redeem points at any time during the Redemption Period as set forth in Section F below. Participants can collect points by the methods set forth in Section E below. All points collected during previous phases of the Program are carried over into the current phase as of January 1, 2011, but Sponsor may expire points from previous phases upon reasonable notice to Participant.