City name changes in India began to take place in 1996 with first Bombay becoming Mumbia, followed by Madras becoming Chennai and then Trivandrum becoming Thirvananthapuram. This is said to be to wipe out traces of the British colonial legacy. In Jan 2001 the state government changed the name of Calcutta to Kolkata. This change is not as dramatic as some of the other changes because the city has always been Kolkata in the Bengali language and Kolkata is in West Bengal. The word Calcutta is an Anglicised version of Kolkata which derives from the original Kalikata.
Ta for the stars, but I can't help thinking Einstein deserved them more! After all, he gave you a correct answer, I just made a joke! Still, ta all the same.