Loyalty Day (Día de la lealtad) is observed in Argentina every October 17. This memorial day commemorates the massive labor demonstration that took place at May Square, where thousands of workers and their families demanded the release of military officer Juan Perón, who had been jailed on Martín García island. The demonstration was sparked by Perón's arrest on October 10, 1945, following his ousting from office just days earlier. The event marked a significant moment in Argentine history, as it catalyzed the rise of the Peronism movement. Perón was released on the same day of the demonstration, and he later became President of Argentina, serving from 1946 to 1955. Loyalty Day is remembered not only for this pivotal event but also as a celebration of the labor movement in Argentina.