Remembrance Day.

Remembrance Day is a special day set aside to remember all the men and women who were killed during the two World Wars and other conflicts. Remembrance Sunday is held on the Second Sunday in November. It is usually on November 11 in Britain.
A national ceremony takes place at the Cenotaph in Whitehall, in London. People leave small crosses to remember a family member who died in war.

The "Last Post" is traditionally played to introduce the two minutes silence in Remember Day ceremonies.
Poppy is the symbol of Remember Day. People on this date wear an artificial poppy.

Never forget.  ஐ

A small cross with poppy.

This is the symbol of Remembrance Day.