The Zulu calendar is a traditional lunisolar system used by the Zulu people of South Africa, beginning its new year with the new moon of uMandulo (which corresponds to September in the Gregorian calendar). It is divided into two main seasons—summer (iHlobo) and winter (ubuSika)—and consists of 13 lunar months, with the 12 standard months lasting roughly 28 days each. To align the calendar with nature, an intercalary month called iNdida (lasting four to five days) is added, though disagreements over the correct month would arise about every three years, leading the extra month to be nicknamed "the month that puzzles men" (Ndid'amDoda). These disputes were traditionally settled by consensus or by observing the heliacal rising of the Pleiades constellation, as documented by missionary James Macdonald. The calendar is marked by important cultural festivals such as Umkhosi Wokweshwama (First Fruits) and Umkhosi woMhlanga (Reed Dance), as well as regional events like the uMathayi Marula Festival held by the Tembe clan.