The Simchat Torah celebration of today is of later rabbinic and customary origin. The day (but not the name) is mentioned in the "siddur" of Rav Amram Gaon (9th century CE); the assignment of the first chapter of Joshua as the "haftarah" of the day is mentioned there. The reading of the first section of Genesis immediately upon the conclusion of the last section of Deuteronomy—as well as the name "Simchat Torah"—can be found in the 14th century "halachic" work "Arba'ah Turim." By the 16th century CE, most of the features of the modern celebration of Simchat Torah were in place in some form. The Simchat Torah celebration is now the most distinctive feature of this festival—so much so that in the Land of Israel, where Shemini Atzeret lasts only one day, it is more common to refer to the day as "Simchat Torah" than as "Shemini Atzeret".