What is the significance of 'Yamadeepam' on Dhanteras?

According to Hindu beliefs, 'Yamadeepam' is the sacred ritual of lighting diyas and seeking blessings from Lord Yama (the god of death) on Dhanteras. People traditionally light a four-faced diya during the evening Pradosh Kaal and place it outside the main entrance, facing south. They pray for longevity and protection from untimely death, while some even observe a fast.