In modern Java there are essentially three calendar systems in use:

• The Western calendar, with its 365-day years of twelve months and fifty-two 7-day weeks. This is the dominant calendar for modern life, used for all types of commerce, intra-national and international communications.

• The Islamic Hijriah calendar, whose 12 months of 29 or 30 days are based on a lunar cycle. This system is used to mark days of religious importance for Javanese and other Muslims in this overwhelmingly Islamic nation, including the beginning and end of the fasting month, the Prophet's birthday, the Ascension, and so on.

• The Javanese "calendar complex". Included here are the Saka calendar (which more or less parallels the Islamic calendar), and several more uniquely Javanese cycles (pasaran, wetonan, pawukon, mangsa) which are not directly related to the Saka, but in many cases tie in with it in interesting ways. As a whole, this is the primary time-keeping system for all matters having cultural, historical, and metaphysical (as opposed to "religious") significance for the Javanese.

The remainder of this page explains the organization of the Javanese calendar, and provides a few notes on the historical and modern significance of the various cycles.

Pasaran

This ancient cycle comes from a time when most of the Javanese population lived in tightly knit village clusters which converged at a market center (pasar) where the cluster's inhabitants gathered once every five days to buy and sell. Itinerant merchants linked groups of five village clusters together into marketing networks, moving to a different market on each day of the five-day cycle. On Legi they would trade at village market A, on Pahing they would move to market B, and so on. The remnants of this system are still visible today in cities such as Surakarta, where Pasar Legi, Pasar Pon, and Pasar Kliwon now refer to municipal districts that were once part of a rotating market arrangement.

As rotating market networks have long been replaced by permanent daily market centers, the pasaran week now has little significance on its own. Although many people still believe that each pasaran day imparts certain general characteristics to those born under it, more often this 5-day week is combined with the 7-day Western/Arabic week to form the single most widespread divinatory tool in Javanese culture, as well as the most common method of determining the proper time for the holding of important rituals: the Wetonan cycle.

Wetonan

The phenomenon of coincidence (as in the literal meaning, "to coincide") is one of the central pillars of Javanese aesthetics. Javanese gamelan music, wherein individual instrumental melodies diverge from each other and then converge again upon important structural tones, is an obvious example. Similarly in the wetonan calendar cycle, the periodic coincidence of two independent time-keeping systems has a significance whose source is far deeper within the spiritual fabric of the culture than mere surface intellectualization.

First, here are the Javanese names for the seven days in the Western or Arabic 7-day week:
 

Superimposing this 7-day week with the 5-day pasaran week, we get the following series, which repeats itself ad infinitum every thirty-five days:

This cycle makes up the most typical Javanese "month" (there are others, as will be explained). It has no fixed starting or ending point, and successive groups of thirty-five days are neither assigned names nor grouped into a Javanese "year". If you were born, say, on Kemis Wagé, then every thirty-five days the wheels of the 5- and 7-day weeks click together again on Kemis Wagé and it is your Javanese "birthday" (your weton).

This cycle figures prominently in a great number of traditional divinitory systems, from predicting human character, fate, and vocational talents, to determining compatible partners in marriage, gambling strategies, and auspicious days for practically any activity you can think of. It also figures in the timing of many ritual meals (slametan). Even spirits and devils are said to have their favorite days for carousing, the eve of Jumat Kliwon being the most popular!
 

Pawukon

Sorry folks—this section has been under construction for so long even I'm wondering if I'll ever get to it. Don't hold your breath.

Pranata Mangsa

This 365-day cycle is divided into twelve "seasons" (mangsa) of uneven length, whose names simply translate as the ordinal numbers 1-12. It was once widely used to time the planting and harvesting of various crops, but now seems to have mostly fallen out of use. The cycle begins near the Summer Solstice, towards the middle of the dry season in Java. One author gives the corresponding dates of the Western calendar as follows:

As a divination tool, the Pranata Mangsa is used in almost precisely the same way as Western Sun-signs to predict character traits of persons born during that time period. In this way, it is perhaps the closest thing the Javanese have to a horoscope system related to astronomical factors, albeit indirectly (i.e., the weather patterns produced by the Earth's revolution about the Sun). However, it is still unclear how widespread this system was in the past, and very few people seem to know much about it today. At least one modern practitioner of this system uses the wetonan and pawukon cycles in conjunction with the pranata mangsa, synthesizing the various interpretations to give a more specific description of a client's character and fate.

The Saka Calendar

Windu

This cycle forms the largest unit of time in the Javanese Saka calendar. There are four windu, each of which is eight Javanese years in length:

A Windu is sort of like a Javanese decade. It is 2835 days long, or exactly 81 repetitions of the 35-day wetonan cycle. Windu do not seem to have much significance in Javanese divination or horoscopy of the present day. However, there is some evidence that they were once used by learned men of the palaces (pujangga) to predict the general trends of an age. The Primbon Betaljemur (article 312), for example, provides this cryptic description of Windu Adi, which we will have entered on April 28, 1998:

A king crowned during this time will enjoy a long life. Nevertheless, many people will act brashly towards their parents and masters.

While the Windu cycle no longer appears to hold a position of much importance in the popular mind, the passing of a windu (whether in the life of an individual or in the "life" of a business) is nevertheless still seen as something of a milestone for many tradition-minded Javanese, and befitting of a proper ritual feast (slametan).

Tahun

Within each windu, the 8 years (tahun) are named as follows:

Wulan

In each year there are 12 lunar months, called wulan. Each Javanese Saka month has either 29 or 30 days, and roughly parallels the Islamic Hijriah calendar.