According to Livy, Numa's calendar was lunisolar with lunar months and several intercalary months spread over nineteen years so that the Sun returned in the twentieth year to the same position it had in the first year. （Livy, History of Rome互联网档案馆的存檔，存档日期2005-03-24. 1.19） （William Smith, A Dictionary of Greek and Roman Antiquities （London: 1875） "Calendarium （页面存档备份，存于互联网档案馆）", Year of Numa）
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etext.lib.virginia.edu
According to Livy, Numa's calendar was lunisolar with lunar months and several intercalary months spread over nineteen years so that the Sun returned in the twentieth year to the same position it had in the first year. （Livy, History of Rome互联网档案馆的存檔，存档日期2005-03-24. 1.19） （William Smith, A Dictionary of Greek and Roman Antiquities （London: 1875） "Calendarium （页面存档备份，存于互联网档案馆）", Year of Numa）
web.archive.org
According to Livy, Numa's calendar was lunisolar with lunar months and several intercalary months spread over nineteen years so that the Sun returned in the twentieth year to the same position it had in the first year. （Livy, History of Rome互联网档案馆的存檔，存档日期2005-03-24. 1.19） （William Smith, A Dictionary of Greek and Roman Antiquities （London: 1875） "Calendarium （页面存档备份，存于互联网档案馆）", Year of Numa）
