Singh, who assumed office on May 22, 2009 for the second consecutive term, already has the distinction of being the third longest serving Prime Minister of the country after Nehru and his daughter Indira who ruled the country for 17 and 16 years respectively.
Singh's predecessor Atal Bihari Vajpayee had hoisted the tricolour from the Red Fort six times from 1998 to 2003.
The historic Mughal monument has seen Nehru, the first Prime Minister of independent India, unfurling the national flag 17 times. He was followed by his daughter Indira Gandhi, who got the honour 16 times.
Nehru first hoisted the tricolour at the Red Fort on August 15, 1947 after India became independent.
Singh, the country's 14th Prime Minister, first hoisted the tricolour on August 15, 2004, nearly four months after he assumed office in May.