Significance
Ganesh Chaturthi celebrates the birth of Lord Ganesha, the elephant-headed god of wisdom, prosperity and the remover of obstacles (Vighnaharta). It is observed with great grandeur, especially in Maharashtra.
The ten-day festival ends with Anant Chaturdashi, when the idols are immersed (Visarjan).
Rituals
Clay idols of Ganesha are installed at homes and pandals, worshipped during the madhyahna (midday) muhurat with modaks, durva grass and red flowers, and celebrated with aartis for one-and-a-half to ten days before the farewell immersion amid chants of "Ganpati Bappa Morya."
How the date is fixed
Ganesh Chaturthi falls on the Chaturthi of Bhadrapada Shukla paksha, decided by the tithi at midday (madhyahna), Ganesha's birth-time, so the madhyahna muhurat is shown above for your location.