Chhath Puja is an Indian thanksgiving festival devoted to the Sun God Surya and his wife Usha. People during Chhath Puja thank the Sun God for sustaining and supporting life on Earth and seek his protection and blessings.
In Hinduism, Sun is considered to be the God of energy and lord of the life-force. Sun is also considered as the source of healing too. Hindus believe that the sun helps to cure many illnesses and diseases such as leprosy, etc.
Sun is also considered to be the symbol of stability and prosperity. Therefore, people worship Sun God during Chhath Puja for longevity and prosperity of family members, friends, and beloved ones.
Chhath Puja is not a gender-specific festival. Also, it is believed that once a family starts performing Chhath Puja, it is their duty to perform it every year and pass it on to the following generations. The festival is skipped only if there happens to be a death in the family that year.