They will be posted in the daily intinerary which will be left in your stateroom each night for the next days activities.
You will not be able to find this out prior to your departure as schedules are constantly changing and that information is very rarely given in advance.
FBandA, Be sure to catch the ice show, times and days will be in the daily paper a few days into cruise. Someone from your group will have to go down and pick up the "free" tickets when they start giving them out..