Why does kolkata experience noon sun exactly overhead twice a year?

Kolkata, located at approximately 22°34'N latitude, does not experience the noon sun exactly overhead twice a year. The cities that lie on or near the Tropic of Cancer (23°26'N) experience this phenomenon.

Only locations between the Tropic of Cancer and the Tropic of Capricorn experience the phenomenon of the noon sun being directly overhead at some point during the year. This occurs due to the Earth's axial tilt and its revolution around the Sun. As the Earth orbits the Sun, different parts of the planet are tilted towards or away from the Sun, causing the position of the noon sun to vary.