Module calendrica-mayan
Mayan and Aztec calendar conversions.
Ported from "Calendrical Calculations" (4th edition) by Nachum Dershowitz and Edward M. Reingold. Original Lisp code (CALENDRICA 4.0) is Apache 2.0 licensed.
Info:
- Release: 0.1 2026-07-19
Functions
| fixed_from_mayan_long_count (count) | Fixed date corresponding to Mayan long count `count`. |
| mayan_long_count_from_fixed (date) | Mayan long count date {baktun,katun,tun,uinal,kin} of fixed `date`. |
| mayan_haab_from_fixed (date) | Mayan haab date {month, day} of fixed `date`. |
| mayan_tzolkin_from_fixed (date) | Mayan tzolkin date {number, name} of fixed `date`. |
| aztec_xihuitl_from_fixed (date) | Aztec xihuitl date {month, day} of fixed `date`. |
| aztec_tonalpohualli_from_fixed (date) | Aztec tonalpohualli date {number, name} of fixed `date`. |
| mayan_haab_on_or_before (haab, date) | Latest fixed date on or before `date` with Mayan Haab date `haab`. |
| mayan_tzolkin_on_or_before (tzolkin, date) | Latest fixed date on or before `date` with Mayan Tzolkin date `tzolkin`. |
| mayan_calendar_round_on_or_before (haab, tzolkin, date) | Latest fixed date on or before `date` with Mayan Calendar Round `haab`+`tzolkin`. |
| mayan_year_bearer_from_fixed (date) | Year bearer of fixed `date` in the Mayan calendar. |
| aztec_xihuitl_on_or_before (xihuitl, date) | Latest fixed date on or before `date` with Aztec Xihuitl date `xihuitl`. |
| aztec_tonalpohualli_on_or_before (tonalpohualli, date) | Latest fixed date on or before `date` with Aztec Tonalpohualli date `tonalpohualli`. |
| aztec_xiuhmolpilli_from_fixed (date) | Aztec Xiuhmolpilli (52-year cycle) designation for fixed `date`. |
Functions
- fixed_from_mayan_long_count (count)
-
Fixed date corresponding to Mayan long count `count`.
Parameters:
- count table Mayan long count date {baktun,katun,tun,uinal,kin}.
Returns:
-
number
Fixed date.
- mayan_long_count_from_fixed (date)
-
Mayan long count date {baktun,katun,tun,uinal,kin} of fixed `date`.
Parameters:
- date number Fixed date.
Returns:
-
table
{baktun, katun, tun, uinal, kin}
- mayan_haab_from_fixed (date)
-
Mayan haab date {month, day} of fixed `date`.
Parameters:
- date number Fixed date.
Returns:
-
table
{month, day}
- mayan_tzolkin_from_fixed (date)
-
Mayan tzolkin date {number, name} of fixed `date`.
Parameters:
- date number Fixed date.
Returns:
-
table
{number, name}
- aztec_xihuitl_from_fixed (date)
-
Aztec xihuitl date {month, day} of fixed `date`.
Parameters:
- date number Fixed date.
Returns:
-
table
{month, day}
- aztec_tonalpohualli_from_fixed (date)
-
Aztec tonalpohualli date {number, name} of fixed `date`.
Parameters:
- date number Fixed date.
Returns:
-
table
{number, name}
- mayan_haab_on_or_before (haab, date)
-
Latest fixed date on or before `date` with Mayan Haab date `haab`.
Parameters:
- haab table Mayan Haab date {month, day}.
- date number Fixed date.
Returns:
-
number
Fixed date.
- mayan_tzolkin_on_or_before (tzolkin, date)
-
Latest fixed date on or before `date` with Mayan Tzolkin date `tzolkin`.
Parameters:
- tzolkin table Mayan Tzolkin date {number, name}.
- date number Fixed date.
Returns:
-
number
Fixed date.
- mayan_calendar_round_on_or_before (haab, tzolkin, date)
-
Latest fixed date on or before `date` with Mayan Calendar Round `haab`+`tzolkin`.
Returns BOGUS if the combination is impossible.
Parameters:
- haab table Mayan Haab date {month, day}.
- tzolkin table Mayan Tzolkin date {number, name}.
- date number Fixed date.
Returns:
-
number
Fixed date or BOGUS.
- mayan_year_bearer_from_fixed (date)
-
Year bearer of fixed `date` in the Mayan calendar.
Parameters:
- date number Fixed date.
Returns:
-
number
Year bearer.
- aztec_xihuitl_on_or_before (xihuitl, date)
-
Latest fixed date on or before `date` with Aztec Xihuitl date `xihuitl`.
Parameters:
- xihuitl table Aztec Xihuitl date {month, day}.
- date number Fixed date.
Returns:
-
number
Fixed date.
- aztec_tonalpohualli_on_or_before (tonalpohualli, date)
-
Latest fixed date on or before `date` with Aztec Tonalpohualli date `tonalpohualli`.
Parameters:
- tonalpohualli table Aztec Tonalpohualli date {number, name}.
- date number Fixed date.
Returns:
-
number
Fixed date.
- aztec_xiuhmolpilli_from_fixed (date)
-
Aztec Xiuhmolpilli (52-year cycle) designation for fixed `date`.
Returns BOGUS during Nemontemi (the 5 unlucky days).
Parameters:
- date number Fixed date.
Returns:
-
table or number
Tonalpohualli date {number, name} or BOGUS.