# Pentecontad calendar

> Mesopotamian calendar, whose year consists of 7 periods of 50 days, with an annual supplement of 15 or 16 days

**Wikidata**: [Q6593547](https://www.wikidata.org/wiki/Q6593547)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Pentecontad_calendar)  
**Source**: https://4ort.xyz/entity/pentecontad-calendar


## References

1. Quora