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Some sources state that the Julian calendar was designed by Aristarchus of Samos, although it is not clear where this conclusion originates. Ptolemy III Euergetes, Aristarchus' contemporary, did indeed decree a reform of the Egyptian calendar in 238 BC, but it was never implemented. The reform, however, would have added an extra day (leap day) to the 365-day Egyptian calendar every four years, a feature shared by the Julian calendar.