21 February per Saiful Islam Shamim

In respect of the language martyrs (see Language Movement Day) — the lion-hearted students Rafiq, Jabbar, Salam, Borkot and so on who died during a protest at the University of Dhaka on February 21, 1952 — the people in Bangladesh celebrate International Mother Language Day by laying down flowers to the Martyr's Monument (Shaheed Minar) and replications of that monument. The people organize social gatherings, where they honor their language and culture, and hold literary competitions, draw A