The full name of this calendar is Spiral Into Madness, but you can use To Madness for short.
The year has 365 days on regular years, 366 days on leap years. The months of the year start at 37 days then become shorter and shorter until they vanish and the year disappears into oblivion. Then a new year begins.
| January | February | March | April | May | June | July | August | September | October |
|---|---|---|---|---|---|---|---|---|---|
| 37 | 35 | 33 | 31 | 29 | 27 | 25 | 23 | 21 | 19 |
| November | December | Anguish | Stasis | Reprieve | Delusion | Demons | Tatters | Absurdum | Insanity (Leap day) |
| 17 | 15 | 13 | 11 | 9 | 7 | 5 | 5 | 3 | 1 |
The months of the year, a.k.a. Spiral of Madness
Leap year rules[]
Leap days are added to the year in a 128-year cycle.
The first leap year of a cycle is the 16th, then every four years until the 60th. Leap years start again on the 72nd year and pause on the 92nd. They resume on the 100th year as follows:
| Every 4 years, 16 to 60 | 104 | 116 | 122 | 126 |
| Every 4 years, 72 to 92 | 108 | 118 | 123 | 127 |
| 100 | 114 | 121 | 125 | 128 |
Most leap days are concentrated near the end of the cycle.
The mean year length is 365 + 31/128 = 365.2421875 days.
The epoch of this calendar is set to Sunday 2 January 2050 which marks the beginning of a new cycle of madness.