Chaga Conk Semi-Permanent Calendar

The Chaga Conk calendar groups days into panniers of ten or eleven days in alternation.

A short pannier lasts ten days. It begins on a Sunday and ends on a Tuesday.

A big pannier lasts eleven days. It begins on a Wednesday and ends on a Saturday.

Three panniers make one month, which means months alternate between 31 and 32 days. The first month of the year is shorter: it contains only two panniers on a regular year (21 days). The last month of a regular year has its third pannier replaced with a leap week, which is a standard 7-day week starting on a Sunday and ending on a Saturday. Its length is 28 days.

That makes a regular year length of 364 days or 52 weeks.

Regular year
11	10	10	11	10
	Jaapia	Fusarium	Maras	Aspergil
Melliol		Gymnos	Julella	Aureoconid
Septobasid		Ochropor	Neolecta	Dacrymyce*

Leap Years[]

On the year leading to a leap year the last month of the year gets three full panniers instead of a leap week (31 days). The year length becomes 367 days or 35 panniers.

Year leading to a leap year
11	10	10	11	10
	Jaapia	Fusarium	Maras	Aspergil
Melliol		Gymnos	Julella	Aureoconid
Septobasid		Ochropor	Neolecta	Dacrymyce

That means a leap year begins on a Wednesday and not a Sunday like other years. The first month consists of a big pannier followed by two leap weeks (25 days) to compensate for the skipped leap week of the previous year. The length of a leap year is 368 days.

Leap year
11	10	11	10
Jaapia*	Fusarium	Maras	Aspergil
Melliol	Gymnos	Julella	Aureoconid
Septobasid	Ochropor	Neolecta	Dacrymyce*

The calendar is semi-permanent: Jaapia has two different configurations depending on the year being a regular year or a leap year. Dacrymyce can get an extra three days, if the next year is a leap year.

Leap Year Cycles[]

The leap year cycle goes for 90 years with 16 leap years. There is a long leap year cycle of 400 years that matches the Gregorian calendar cycle (365.2425 days in a year on average).

The leap years are distributed as follows:

Leap years in a long cycle
6	12	18	24	29	34	40	46	52	57
62	68	74	80	85	90	96	102	108	114
119	124	130	136	142	147	152	158	164	170
175	180	186	192	198	204	209	214	220	226
232	237	242	248	254	260	265	270	276	282
288	294	299	304	310	316	322	327	332	338
344	350	355	360	366	372	378	384	389	394
400

The epoch of the calendar is Wednesday 1 January 1800, which is the last year of a 400-year cycle.

Year Start Dates[]

Start date of some Chaga Conk years
Week day	Gregorian date	Chaga Conk year
Wednesday	1 January 2020	220 (leap)
Sunday	3 January 2021	221
Sunday	2 January 2022	222
Sunday	1 January 2023	223
Sunday	31 December 2023	224
Sunday	29 December 2024	225
Wednesday	31 December 2025	226 (leap)
Sunday	3 January 2027	227
Sunday	2 January 2028	228
Sunday	31 December 2028	229