The Karen calendar is based mainly on signs from nature and does not follow the commonly recognised Gregorian calendar system. The moon cycle, behaviour of insects, birds and other animals, as well as the weather are the main factors influencing the Karen calendar. Signs from nature form the basis of the Karen agricultural schedule and also determine the timing of ceremonies and other aspects of daily life. Weather is also predicted using a combination of these natural signs. When the Karen hear the bird Toe Kwa (Blue-throated barbet) sing “Ku Klo, Ku Klo”, they know that it is Tha Lay, and the time for Karen New Year.
This happens around January after the harvest is finished. The farmers will use this time to choose new land for cultivation. The singing of Toe Kwa intensifies in February and March and begins to be accompanied by the Thee Thway insects. This is a signal to the farmers to begin clearing the land. If there are many Thee Thway insects making noise then the farmers know to expect rain. Their singing is a warning that rain will begin in a few weeks and that villagers are running out of time for the land to dry and be burned.
During the raining season, when the Day Baw kaw frog is heard croaking, it is a warning that heaving rain is looming and it is time to go home or prepare for rainfall. The day Kwoh frog lets the farmers know that the sun will soon set.
| Schedule for cultivation | |
| January | Karen New Year (Tha Lay). Free tiime after harvest. Selling of extra products. Daily work for extrra income. Rebuild or repari houses. |
| February | Site selection for new season. Begin clearing the land for cultivation. |
| March | Clearing and drying of the land. Prepare materials to build shelters in the field. |
| April | Clearing and burning of the land. Building field shelters. Collection of firewood. Begin planting. |
| May | Planting of rice and vegetables. Collection of firewood. Building field shelters. |
| June | Clear the weeds from the land. |
| July | Ploughing fields for rice cultivation (flatland paddy farming). Thet Ku ceremony. |
| August | La Ku Ki Su ceremony. Make wishkey. |
| September | Prepare for harvest. Weave mats. Make winowing trays. Build rice barn. |
| October | Prepare for harvest. Weave mats. make winowing trays. Build rice barn. Begin rice harvest. Pound rice. |
| November | Rice harvest. Pound rice. Conduct Ther Tor Toe ceremony. Harvest other crops. Seed collection. |
| December | Harvest other crops. Seed collection. Make whiskey. Ther Tor Toe ceremony. Hu Plue ceremony. Karen New Year (Tha Lay) |