The solar calendar used by the Jewish sect around the caves of Qumran used a perfect year of 364 days or 52 weeks. It may have used a cycle of 294 years reckoned to equal 293 solar years, which gives a mean solar year of 365.24232 days, but the actual leap rule used, if any, is unknown.
References
See Also
- Enoch Calendar: similar calendar, probably related, perhaps even the same
- 28/293 Calendar: uses the alleged cycle of 293 solar years