भारत में प्रतिवर्ष 'राष्ट्रीय किसान दिवस' किस तिथि को मनाया जाता है?

In which year did the Government of India declare Swami Vivekananda's birth anniversary as National Youth Day?

On which date is National Youth Day observed in India to mark the birth anniversary of Swami Vivekananda?