Chhath Puja 2025 will be celebrated from October 25 to October 28 in Bihar and other regions. Know the complete day-wise schedule with dates for Nahay Khay, Kharna, Sandhya Arghya and Usha Arghya. Learn about the significance of Chhath Mahaparv, rituals of offering arghya to Lord Surya and devotion to Chhathi Maiya.