Variable: calendar-bahai--nawruz-reference-dates

calendar-bahai--nawruz-reference-dates is a variable defined in cal-bahai.el.gz.

Value

((2015 3 21) (2016 3 20) (2017 3 20) (2018 3 21) (2019 3 21)
 (2020 3 20) (2021 3 20) (2022 3 21) (2023 3 21) (2024 3 20)
 (2025 3 20) (2026 3 21) (2027 3 21) (2028 3 20) (2029 3 20)
 (2030 3 20) (2031 3 21) (2032 3 20) (2033 3 20) (2034 3 20)
 (2035 3 21) (2036 3 20) (2037 3 20) (2038 3 20) (2039 3 21)
 (2040 3 20) (2041 3 20) (2042 3 20) (2043 3 21) (2044 3 20)
 (2045 3 20) (2046 3 20) (2047 3 21) (2048 3 20) (2049 3 20)
 (2050 3 20) (2051 3 21) (2052 3 20) (2053 3 20) (2054 3 20)
 (2055 3 21) (2056 3 20) (2057 3 20) (2058 3 20) (2059 3 20)
 (2060 3 20) (2061 3 20) (2062 3 20) (2063 3 20) (2064 3 20))

Documentation

Official Naw-Rúz dates from the Bahá’í World Centre (2015-2064).

Each entry is (GREGORIAN-YEAR MONTH DAY). These dates are extracted from the official ICS calendar file and serve as the authoritative reference for verifying the astronomical calculations.

The dates show that Naw-Rúz falls on March 20 or 21, depending on when the vernal equinox occurs relative to sunset in Tehran.

Source Code

;; Defined in /usr/src/emacs/lisp/calendar/cal-bahai.el.gz
;;; ======================================================================
;;; Verification and Testing
;;; ======================================================================

;; The following code verifies the astronomical calculations against
;; official dates published by the Bahá’í World Centre.
;;
;; BACKGROUND: 2014 Calendar Reform
;; --------------------------------
;; On 10 July 2014, the Universal House of Justice announced provisions
;; for the uniform implementation of the Badí' calendar, effective from
;; Naw-Rúz 172 BE (March 2015).  The key provisions are:
;;
;; 1. NAW-RÚZ DETERMINATION:
;;    "The Festival of Naw-Rúz falleth on the day that the sun entereth
;;    the sign of Aries, even should this occur no more than one minute
;;    before sunset."  Tehran is the reference point for determining the
;;    moment of the vernal equinox.  If the equinox occurs before sunset
;;    in Tehran, that day is Naw-Rúz; otherwise, the following day is.
;;
;; 2. TWIN HOLY BIRTHDAYS:
;;    "They will now be observed on the first and the second day
;;    following the occurrence of the eighth new moon after Naw-Rúz,
;;    as determined in advance by astronomical tables using Ṭihrán as
;;    the point of reference."
;;
;; VERIFICATION APPROACH
;; ---------------------
;; The functions below compare calculated dates against official data
;; from the Bahá’í World Centre, covering the 50-year period from
;; 172 BE (2015 CE) to 221 BE (2064 CE).  This data was extracted from
;; the official ICS calendar file distributed by the Bahá’í World Centre.
;;
;; The verification confirms:
;; - Naw-Rúz dates: Calculated using `solar-equinoxes/solstices' for the
;;   vernal equinox and `solar-sunrise-sunset' for Tehran sunset times.
;; - Twin Holy Birthdays: Calculated using `lunar-new-moon-on-or-after'
;;   to find the eighth new moon after Naw-Rúz.
;;
;; To run the verification:
;;   M-x calendar-bahai-verify-calculations RET

(defconst calendar-bahai--nawruz-reference-dates
  '((2015 3 21) (2016 3 20) (2017 3 20) (2018 3 21) (2019 3 21)
    (2020 3 20) (2021 3 20) (2022 3 21) (2023 3 21) (2024 3 20)
    (2025 3 20) (2026 3 21) (2027 3 21) (2028 3 20) (2029 3 20)
    (2030 3 20) (2031 3 21) (2032 3 20) (2033 3 20) (2034 3 20)
    (2035 3 21) (2036 3 20) (2037 3 20) (2038 3 20) (2039 3 21)
    (2040 3 20) (2041 3 20) (2042 3 20) (2043 3 21) (2044 3 20)
    (2045 3 20) (2046 3 20) (2047 3 21) (2048 3 20) (2049 3 20)
    (2050 3 20) (2051 3 21) (2052 3 20) (2053 3 20) (2054 3 20)
    (2055 3 21) (2056 3 20) (2057 3 20) (2058 3 20) (2059 3 20)
    (2060 3 20) (2061 3 20) (2062 3 20) (2063 3 20) (2064 3 20))
  "Official Naw-Rúz dates from the Bahá’í World Centre (2015-2064).
Each entry is (GREGORIAN-YEAR MONTH DAY).  These dates are extracted
from the official ICS calendar file and serve as the authoritative
reference for verifying the astronomical calculations.

The dates show that Naw-Rúz falls on March 20 or 21, depending on
when the vernal equinox occurs relative to sunset in Tehran.")