2023 calendar

Many people around the world live by different calendars, and for some this leads to some unusual birthday celebrations, says Erin Craig.

[studied calendar use in the Sahel and the Sahara](https://ui.adsabs.harvard.edu/abs/2015hae..book.1107O/abstract), coined the term "calendar pluralism" to describe the coexistence of multiple timekeeping systems, much as legal pluralism describes societies with multiple systems of law. In 1880s Beirut, the Gregorian was just [one of four calendars](https://www.google.co.uk/books/edition/The_Global_Transformation_of_Time/R5_XCgAAQBAJ) in everyday use. In December, South Korea passed a bill [dispensing with traditional ages](https://www.koreatimes.co.kr/www/nation/2022/12/281_341383.html) on the grounds that the multi-age system is economically inefficient. [1430s calendar reform](https://www.google.co.uk/books/edition/Handbook_of_Archaeoastronomy_and_Ethnoas/vqkGrgEACAAJ?hl=en) – one adapted from the Chinese calendar, one from the Arabic. [largely interpreted as a cost-cutting measure](https://www.bbc.co.uk/programmes/p049yxsh?ocid=socialflow_facebook). As with the World Calendar movement of the late 19th Century, the 21st Century has seen a push toward calendar unity for economic reasons. A product of religious doctrine and Renaissance science, the Gregorian calendar was created to correct drift between the Catholic liturgical year (then based on the Julian calendar) and the actual solar year. It's not exactly monotemporalism – the Bikram Sambat contains several layers of cultural and religious timekeeping within its solar year, 12 lunar months, and six seasons – but for a Hindu living in Kathmandu this one system covers all aspects of daily life from fast days to payday. [Stonehenge was a giant calendar](https://www.bbc.com/news/uk-england-bristol-60573527)), but I wasn't used to thinking of other calendars as current. (Symbolically, this can also happen [at Lunar New Year](https://www.bbc.com/travel/article/20180219-in-south-korea-age-is-measured-in-bowls-of-soup).) Moreover, Koreans can choose whether to celebrate their personal birthdays in the Gregorian or the traditional lunar calendar. Moroccans are [praying in 1444](https://www.aljazeera.com/news/2022/7/29/islamic-new-year-and-the-different-calendars-around-the-world) but [farming in 2972](https://gl-news.com/news/the-year-2972-is-commemorated-by-moroccan-berbers/), and Ethiopians are [working their way through 2015], which for them has 13 months. [two to three official ages](https://www.bbc.com/news/world-asia-61117434) at any given time: domestic, international (counting from zero), plus a bonus year when the entire country ages together on 1 January.