হস্তী বর্ষ বা হস্তিবর্ষ শব্দটি প্রথম কবে থেকে ব্যবহৃত হয় ?
The ʿĀmu l-Fīl (, Year of the Elephant) is the name in Islamic history for the year approximately equating to 570 CE. According to some Islamic resources, it was in this year that Muhammad (, consonant letters: m-ħ-m-d) was born. The name is derived from an event said to have occurred at Mecca: Abraha, the Abyssinian, Christian ruler of Yemen, which was subject to the Kingdom of Aksum of Ethiopia, marched upon the Ka‘bah in Mecca with a large army, which included one or more war elephants, intending to demolish it. However, the lead elephant, known as 'Mahmud' (, consonant letters: m-ħ-m-d), is said to have stopped at the boundary around Mecca, and refused to enter. It has been theorized that an epidemic, perhaps caused by smallpox, could have caused such a failed invasion of Mecca. The year came to be known as the Year of the Elephant, beginning a trend for reckoning the years in the Arabian Peninsula. This reckoning was used until it was replaced with the Islamic calendar during the times of ‘Umar. 
Archaeological discoveries in Southern Arabia suggest that Year of the Elephant may have been 569 or 568, as the Sasanian Empire overthrew the Aksumite-affiliated rulers in Yemen around 570. 
570 CE