epochs.hpp

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/*
 
Copyright 2025 Matthew Tolman
 
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
 
   http://www.apache.org/licenses/LICENSE-2.0
 
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
 
*/
 
#ifndef MTCORE_CALENDARS_EPOCHS_HPP
#define MTCORE_CALENDARS_EPOCHS_HPP
 
#include "mtcore.hpp"
 
namespace mtcore::calendars {
  constexpr i32 FIXED_EPOCH               = 0;
  constexpr i32 GREGORIAN_EPOCH           = 1;
  constexpr i32 EGYPTIAN_EPOCH            = -272787;
  constexpr i32 ARMENIAN_EPOCH            = 201443;
  constexpr i32 AKAN_EPOCH                = 37;
  constexpr i32 JULIAN_EPOCH              = -1;
  constexpr i32 BALINESE_PAWUKON_EPOCH    = -1721279;
  constexpr i32 COPTIC_EPOCH              = 103605;
  constexpr i32 ETHIOPIC_EPOCH            = 2796;
  constexpr i32 HEBREW_EPOCH              = -1373427;
  constexpr i32 ICELANDIC_EPOCH           = 109;
  constexpr i32 ISLAMIC_EPOCH             = 227015;
  constexpr f64 JULIAN_DAY_EPOCH          = -1721424.5;
  constexpr i32 MAYAN_LONG_DATE_EPOCH     = -1137142;
  constexpr i32 MAYAN_HAAB_EPOCH          = MAYAN_LONG_DATE_EPOCH - 348;
  constexpr i32 MAYAN_TZOLKIN_EPOCH       = MAYAN_LONG_DATE_EPOCH - 159;
  constexpr i32 UNIX_TIMESTAMP_EPOCH      = 719163;
  constexpr f64 MODIFIED_JULIAN_DAY_EPOCH = 678576;
  constexpr i32 ZOROASTRIAN_EPOCH         = 230638;
 
  // Correlation is based on the fall of Mexico City to Hernán Cortés on August 13, 1521 (Julian)
  constexpr i32 AZTEC_CORRELATION         = 555403;
  constexpr i32 TONALPOHUALLI_CORRELATION = AZTEC_CORRELATION - 104;
  constexpr i32 XIHUITL_CORRELATION       = AZTEC_CORRELATION - 201;
 
  constexpr f64 ARYA_LUNAR_MONTH      = 1577917500.0 / 53433336.0;
  constexpr f64 ARYA_LUNAR_DAY        = ARYA_LUNAR_MONTH / 30.0;
  constexpr i32 OLD_HINDU_SOLAR_EPOCH = -1132959;
  constexpr f64 ARYA_SOLAR_YEAR       = 15779175.0 / 43200.0;
  constexpr f64 ARYA_SOLAR_MONTH      = ARYA_SOLAR_YEAR / 12.0;
  constexpr f64 ARYA_JOVIAN_PERIOD    = 1577917500.0 / 364224.0;
}  // namespace mtcore::calendars
 
#endif  // MTCORE_CALENDARS_EPOCHS_HPP