Last winter it was Feb 14th
http://www.winnipesaukee.com/forums/...inter+carnival
You could contact the Alton Parks and Rec dept and ask them for an estimate of the 2011 date.
http://alton.nh.gov/ParksRec.asp
The ice airport is open as soon as the ice is safe for operation, date managed by Mother Nature but often by mid Jan. Looks like last winter it was ready Jan 8th.
http://www.winnipesaukee.com/forums/...=alton+airport