in various other cultures in Eurasia. It was inscribed on UNESCO's World Heritage List in June 2011. Carpets Carpet weaving is an essential part of the Persian culture, and Persian rugs are said to be one of the most detailed hand-made works of art. Achaemenid rug and carpet artistry is well recognized. Xenophon describes the carpet production in the city of Sardis, stating that the locals take pride in their carpet production. A special mention of Persian carpets is also made by Athenaeus of Naucratis in his Deipnosophistae, as he describes a "delightfully embroidered" Persian carpet with "preposterous shapes of griffins". The Pazyryk carpet, a Scythian pile-carpet dating back to the 4th century BC that is regarded as the world's oldest existing carpet, depicts elements of Assyrian and Achaemenid designs, including stylistic references to the stone slab designs found in Persian royal buildings. Music According to the accounts reported by Xenophon, a great number of singers were present at the Achaemenid court. However, little information is available from the music of that era. The music scene of the Sasanian Empire has a more available and detailed documentation than the earlier periods, and is especially more evident within the context of Zoroastrian musical rituals. Overall, Sasanian music was influential and was adopted in the subsequent eras. Iranian music, as a whole, utilizes a variety of musical instruments that are unique to the region, and has remarkably evolved since the ancient and medieval times. In traditional Sasanian music, the octave was divided into seventeen tones. By the end of the 13th century, Iranian music also maintained a twelve-interval octave, which resembled the western counterparts. Observances The Iranian New Year's Day, Nowruz, which translates to "new day", is celebrated by Persians and other peoples of Iran to mark the beginning of spring on the vernal equinox on the first day of Farvardin, the first month of the Iranian calendar, which corresponds to around March 21 in the Gregorian calendar. An ancient tradition that has been preserved in Iran and several other countries that were under the influence of the ancient empires of Iran, Nowruz has been registered on UNESCO's Intangible Cultural Heritage Lists. In Iran, the Nowruz celebrations (incl. Charshanbe Suri and Sizdebedar) begin on the eve of the last Wednesday of the preceding year in the Iranian calendar and last on the 13th day of the new year. Islamic festivals are also