Nangsue Radu Uposot (The book of the seasons for Uposatha). The content tells how to change the days for performing the Patimokkha ceremony in each season. The monk who recites the text of Patimokkha has to change Pali words which relate to the day in three seasons including rainy season, winter and summer.
1. Rainy season has four months beginning on the first day of the waning moon of the eighth lunar month to on the fifteenth day of the waxing moon of the twelfth lunar month. There are seven times of the Uposatha day and one day of Pavarana (invitation to speak) on the day of the end of the rains-residence.
2. Winter has four months that begins from on the first day of the waning moon of the twelfth lunar month to on the fifteenth day of the waxing moon of the fourth lunar month. There are eight times of the Uposatha day.