The calendar used on the plane Ilfreann follows the natural cycle of seasons.
Each year, the three seasons Summer, Monsoon and Winter come to pass. Each season is divided into two months, as follows:
Summer:
Growth: During the month of growth, the summer starts out cool and slowly builds up to a humid and warm weather
Damp: The month of Damp is called such because of the high humidity of the period. During damp the weather continues growing warmer and more humid, to the point that every morning everything outside is wet due to condensation
Monsoon:
Storm: The start of the monsoon is heralded by massive storms. These storms go on for days on end, and rarely give respite to weary travellers.
Rain: After the massive storms at the start of the monsoon season, the rains keep going for weeks, eventually leading to every river swelling out of it's normal boundaries.
Winter:
Waxing Mist: When the monsoon comes to an end, the weather changes once more, this time producing a permanent fog. At the start of the month, this starts with fog banks in the early morning. Eventually, at the end of the period, the fog is thick enough that one cannot see more than 20 meters ahead even at the height of day.
Waning Mist As the weather warms even further, towards the start of the Summer, the fog slowly fades again.
While these periods and changes in the weather or not punctual, they are regular enough that the actual calendar is tied to them loosely. Each season lasts 120 days, and each month lasts 60 days. Exception to this is Storm, which lasts for 40 days, and Rain which lasts for 80 days.