Simplify the following text for a Grade 4 native English-speaking person.
Original: Remembrance Day is observed on 11 November to recall the official end of World War I on that date in 1918 , as the major hostilities of World War I were formally ended `` at the 11th hour of the 11th day of the 11th month '' of 1918 with the German signing of the Armistice .
Simplified: It is on November 11th to remember the end of World War I on that day in 1918 .