section_path: Year designation/Cycles of years
section_name: Cycles of years
paragraph_text: Cycles of years
  
  Eight tahun makes up a windu. A single windu lasts for 81 repetitions of the wetonan cycle, or 2,835 days (about 7 years 9 months in the Gregorian calendar). The tahun are lunar years, and of shorter length than Gregorian years. The names of the years in the cycle of windu are as follows (in krama/ngoko):
  
  The windu are then grouped into a cycle of four:
  
  The cycles of wulan, tahun, and windu are derived from the Saka calendar.
  
  Windu' are no longer used much in horoscopy, but there is evidence that it was previously used by court officials to predict trends. The passing of a windu is often seen as a milestone and deserving a slametan ritual feast.