Based on the information present in the given passage, you need to write a correct answer to the given question. A correct answer is one that correctly and completely answers the question. Do not write answers that address the question partially or incorrectly. The correct answer must be contained in the given paragraph.
Example: Paragraph- Sent 1: Obama was born on August 4, 1961, at Kapiʻolani Maternity & Gynecological Hospital in Honolulu, Hawaii.
Sent 2: He is the only President to have been born in Hawaii.
Sent 3: He was born to a white mother and a black father.
Sent 4: His mother, Ann Dunham (1942-1995), was born in Wichita, Kansas, of mostly English descent, with some German, Irish, Scottish, Swiss, and Welsh ancestry. Question: How old was Obama's mother when he was born?
Example solution: 19.
Example explanation: Obama was born in 1961. His mother was born in 1942 and 1961-1942=19. Therefore, any of the following responses are considred correct: '19' and 'almost twenty'.

Problem: Paragraph- Sent 1: The Golden Heian Era: The geomancers in 794 decided that Heian-kyo (modern Kyoto) would be an auspicious site for the imperial family.
Sent 2: It was indeed — until 1869.
Sent 3: Grants of tax-free land over the years had been made to Buddhist temples and members of the court aristocracy.
Sent 4: The most powerful families thus carved out for themselves whole regions that were to become the fiefdoms of Japanese feudalism.
Sent 5: By the end of the eighth century the clans had created a hierarchy of shiki, or rights, from the highest to the lowest ranks of society.
Sent 6: The aristocrat or court patron lent his prestige to a powerful provincial proprietor, who employed a competent estate-manager to oversee smallholders, who in turn worked their farms with dependent laborers.
Sent 7: This elaborate structure of interdependent rights and obligations was to serve Japanese society right into the 20th century.
Sent 8: Meanwhile, Heian court life blossomed in an effusion of aesthetic expression.
Sent 9: Princes and princesses judged the merits of birds, insects, flowers, roots, or seashells.
Sent 10: Literary party games held in ornate palace gardens required each guest to compose a small poem as his wine cup floated toward him along a miniature winding channel of water.
Sent 11: Expeditions were organized to the best viewing points for the first spring cherry blossoms, and special pavilions were built to watch the rising of the full moon.
Sent 12: Every gesture, from the most banal opening of an umbrella to the sublimest act of lovemaking, had its appropriate ceremonial.
Sent 13: Conversation often took the form of elegant exchanges of improvised verse.
Sent 14: The changing role of Chinese culture in Japanese life was epitomized in the language itself.
Sent 15: In the absence of an indigenous alphabet, Japanese scholars had with the greatest difficulty tried to adapt the complex ideograms of monosyllabic Chinese to the essentially polysyllabic Japanese.
Sent 16: Thus developed the katakana system used as a vehicle for writing Buddhist names and concepts.
Sent 17: After rival Fujiwara factions had been struggling for years to gain control of the imperial throne, they turned to the Taira and Minamoto armies in 1156 to wage the four-year war that heralded the end of the golden age of the Heian court.
Sent 18: The Taira, controlling the region along the Inland Sea, defeated the Minamoto armies based in the Kanto province east of the capital. 
Question: What time period was Heian-kyo used as a site for the imperial family?.

Solution: From 794 to 1869.