The other highly visible public duty of the Ceremonial Guard is sentry duty at Rideau Hall. The sentries are ceremonial in nature only and do not generally perform actual guard duty, however all are trained military personnel and procedures and orders do exist for the Ceremonial Guard to adopt an armed night guard of Rideau Hall should sufficient security threat arise.
The sentries are posted daily from 9:00AM EST to 5:00PM EST, every hour on the hour. At 9:00 AM the posting corporal – generally a corporal from the junior leadership but sometimes a corporal from the ranks – marches out accompanied by the four sentries, two escorts, and a bagpiper. The corporal, sentries, and escorts are all dressed in full scarlet uniforms and carry rifles with bayonets fixed. The party marches to the Sussex drive gate of Rideau Hall where the first two sentries are posted and read their duties. The party then marches to Rideau Hall itself where the two remaining sentries are posted and read their duties.
Throughout the day Rideau Hall will be visited by the Officer Commanding of the parade and the Company Sergeant-Major. They will generally elect to observe a relief of the sentries, and sometimes the Officer Commanding will take a report from the sentries on duty. The Guard Sergeant for Rideau Hall may also elect to do rounds to check on both of the sentry posts.
(Write up from Wikipedia, pics from Foot Guards)