阴水羊年 (female Water-Goat) 630 or 249 or −523 — to — 阳木猴年 (male Wood-Monkey) 631 or 250 or −522
Year 504 (DIV) was a leap year starting on Thursday of the Julian calendar. At the time, it was known as the Year of the Consulship of Nicomachus without colleague (or, less frequently, year 1257 Ab urbe condita). The denomination 504 for this year has been used since the early medieval period, when the Anno Dominicalendar era became the prevalent method in Europe for naming years.
A major expansion of Copán's ceremonial center, the Acropolis complex, is undertaken by B'alam Nehn (Waterlily Jaguar), the seventh ruler (ajaw) of the southeastern Maya city (approximate date).