Flipkart will have their popular Big Billion Day sale staring on September 29. The sale will compete with Amazon's own Great Indian Festival sale, which is starting on the same day. Both companies are expected to bring great offers to a lot of catergories, including smartphones and gadgets.

Here's a time table of all the categories that will go on sale during the Big Billion Days. The list also marks the dates on which offers for that particular category will commence.