Ganesha Chaturthi, the great Ganesha festival, also known as 'Vinayak Chaturthi' or 'Vinayaka Chavithi' is celebrated by Hindus around the world as the birthday of Lord Ganesha. It is observed during the hindu month of Bhadra (mid-August to mid-September) and the grandest and most elaborate of them, especially in the western India state of Maharashtra, lasts for 10 days, ending on the day of 'Ananta Chaturdashi'.
A life-like clay model of Lord Ganesha is made 2-3 months prior to the day of Ganesh Chaturthi. The size of this idol may vary from 3/4th of an inch to over 25 feet.
On the day of the festival, it is placed on raised platforms in homes or in elaborately decorated outdoor tents for people to view and pay their homage. The priest, usually clad in red silk dhoti and shawl, then invokes life into the idol amidst the chanting of mantras. This ritual is called 'pranapratishhtha'. After this the 'shhodashopachara' (16 ways of paying tribute) follows. Coconut, jaggery, 21 'modakas' (rice flour preparation), 21 'durva' (trefoil) blades and red flowers are offered. The idol is anointed with red unguent or sandal paste (rakta chandan). Throughout the ceremony, Vedic hymns from the Rig Veda and Ganapati Atharva Shirsha Upanishad, and Ganesha stotra from the Narada Purana are chanted.
For 10 days, from Bhadrapad Shudh Chaturthi to the Ananta Chaturdashi, Ganesha is worshipped. On the 11th day, the image is taken through the streets in a procession accompanied with dancing, singing, to be immersed in a river or the sea symbolizing a ritual see-off of the Lord in his journey towards his abode in Kailash while taking away with him the misfortunes of all man. All join in this final procession shouting "Ganapathi Bappa Morya, Purchya Varshi Laukariya" (O father Ganesha, come again early next year). After the final offering of coconuts, flowers and camphor is made, people carry the idol to the river to immerse it.