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.

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.
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