In 1000, the Muslim chronologist al-Biruni described all of the modern rules of the Hebrew calendar, except that he specified three different epochs used by various Jewish communities being one, two, or three years later than the modern epoch.
No ano 1000, o cronista musulmán al-Biruni tamén describiu todas as regras modernas e especificou as tres épocas diferentes usadas por varias comunidades xudaicas diferenciándose por un, dous ou tres anos na época moderna.