October 31 is observed every year as National Unity Day to commemorate the birth anniversary of Sardar Patel, who played a pivotal role in integrating princely states into the Indian Union after Independence. Ekta Nagar, Oct 31 (PTI) Prime Minister Narendra Modi on Saturday paid floral tributes to Sardar Vallabhbhai Patel at the Statue of Unity in Gujarat’s Ekta Nagar, on the former Deputy PM’s 151st.