President Droupadi Murmu extended Chhath Puja greetings, highlighting the festival's message of gratitude to nature, environmental conservation and cultural traditions. Devotees observed Sandhya Arghya on Sunday evening, with the four-day celebrations concluding Monday morning with prayers to the rising Sun. New Delhi: President Droupadi Murmu on Sunday extended warm greetings to the countrymen on the auspicious occasion of Chhath Puja and said that the festival inspires people to express gratitude to nature.