India, Pakistan and Bangladesh were independent from the British rule on August 15th, 1947. Why is it that India celebrates the nation's Independence Day on August 15th while Pakistan celebrates it on August 14th?
The 15th of August was the date chosen by Mountbatten to transfer power, as it was the anniversary of Japan's surrender in World War II.
The act of UK parliament giving independence to India and Pakistan took effect from the 15th of August. The act took effect at midnight, and 14th of August 1947 coincided with 27th day of Ramadan (considered sacred night for Muslims), which is why Pakistan choose that date instead.