Information about the Saka calendar on a Balinese wall calendar
Based on a lunar calendar, the saka year comprises twelve months, or sasih, of 30 days each. However, because the lunar cycle is slightly shorter than 30 days, and the
lunar year has a length of 354 or 355 days, the calendar is adjusted to prevent it losing synchronization with the lunar or solar cycles. The months are adjusted by allocating two lunar days to one solar day every 9 weeks. This day is called ngunalatri,
Sanskrit for "minus one night". To stop the Saka from lagging behind the Gregorian calendar – as happens with the
Islamic calendar, an extra month, known as an intercalary month, is added after the 11th month (when it is known as Mala Jiyestha), or after the 12th month (Mala Sadha). The length of these months is calculated according to the normal 63-day cycle. An intercalary month is added whenever necessary to prevent the final day of the 7th month, known as Tilem Kapitu, from falling in the Gregorian month of December.
The names the twelve months are taken from a mixture of Old Balinese and Sanskrit words for 1 to 12, and are as follows:
Each month begins the day after a new moon and has 15 days of waxing moon until the full moon (Purnama), then 15 days of waning, ending on the new moon (Tilem). Both sets of days are numbered 1 to 15. The first day of the year is usually the day after the first new moon in March.
 Note, however, that Nyepi falls on the first day of Kadasa, and that the years of the Saka era are counted from that date.