code: def next_tzolkin(tzolkin, jd):
      '''For a given tzolk'in day, and a julian day count, find the next occurrance of that tzolk'in after the date'''
      if jd < EPOCH:
          raise IndexError("Input day is before Mayan epoch.")
  
      count1 = _tzolkin_count(*to_tzolkin(jd))
      count2 = _tzolkin_count(*tzolkin)
  
      add_days = (count2 - count1) % 260
      return jd + add_dayf next_tzolkin(tzolkin, jd):
      '''For a given tzolk'in day, and a julian day count, find the next occurrance of that tzolk'in after the date'''
      if jd < EPOCH:
          raise IndexError("Input day is before Mayan epoch.")
  
      count1 = _tzolkin_count(*to_tzolkin(jd))
      count2 = _tzolkin_count(*tzolkin)
  
      add_days = (count2 - count1) % 260
      return jd + add_days
docs: For a given tzolk'in day, and a julian day count, find the next occurrance of that tzolk'in after the date