Lunar Saros 129 occurs at the moon's descending node, repeats sometimes 18 years apart and is called the Saros cycle and is exactly 223 synodic months that can be used to predict eclipses.
The saros (/srs/ (listen)) is a period of exactly 223 synodic months (approximately 6585.3211 days, or 18 years, 11 days, 8 hours) that can be used to predict eclipses of the Sun and Moon. 
