Martyrdom Day of Shaheed Udham Singh is observed in the Indian states of Punjab and Haryana on July 31 each year. This day commemorates the Punjabi revolutionary Udham Singh, who is best known for assassinating Michael O’Dwyer, the former lieutenant governor of Punjab, in retaliation for his role in the Jallianwala Bagh massacre of April 13, 1919. On this day, people participate in marches and flower-laying ceremonies, particularly in Singh's hometown of Sunam. The massacre, which resulted in the deaths of at least 379 unarmed civilians, deeply affected Singh, prompting him to join the revolutionary movement and seek revenge against O’Dwyer. Singh was executed on July 31, 1940, and his death anniversary has since become an official memorial day in Punjab and Haryana, reflecting the polarized views on his actions during the struggle against British colonial rule.