223

https://eclipse.gsfc.nasa.gov/SEsaros/SEsaros.html

The periodicity and recurrence of eclipses is governed by the Saros cycle, a period of approximately 6,585.3 days (18 years 11 days 8 hours). It was known to the Chaldeans as a period when lunar eclipses seem to repeat themselves, but the cycle is applicable to solar eclipses as well.

The Saros arises from a natural harmony between three of the Moon's orbital periods (circa 2000 CE):

Synodic Month (New Moon to New Moon) = 29.530589 days = 29d 12h 44m 03s

Anomalistic Month (perigee to perigee) = 27.554550 days = 27d 13h 18m 33s

Draconic Month (node to node) = 27.212221 days = 27d 05h 05m 36s

One Saros is equal to 223 synodic months. However, 239 anomalistic months and 242 draconic months are also equal to this same period (to within a couple hours)!

223 Synodic Months = 6585.3223 days = 6585d 07h 43m

239 Anomalistic Months = 6585.5375 days = 6585d 12h 54m

242 Draconic Months = 6585.3575 days = 6585d 08h 35m