11/11/11 in Australia

( Also known as remembrance day) The 11th hour of the 11th day during the 11th month is a day where you have a minute of silence in Australia. Remembrance Day in Australia is dedicated to Australians who died as a result of war, particularly from World War I onward. A minute of silence is dedicated to the deceased, especially for soldiers who died fighting to protect the nation.
You don't use this in a sentence instead, you would say 'Lest we Forget' As a reference to this day. (This does not just happen in Australia, Other countries as well,)