In the 19th century, the solar month system or "pranata mangsa" was much better known among Javanese than the civil or religious year. The cycle is clearly of Javanese origin, since the specific application to their climate does not match other territories in the Indonesian archipelago, as well as the usage of Javanese names for the months. Although the cycle matches the weather pattern well, it is still clearly somewhat arbitrary, as can be seen in the lengths of the months.