Function: calendar-persian-year-from-absolute

calendar-persian-year-from-absolute is a byte-compiled function defined in cal-persia.el.gz.

Signature

(calendar-persian-year-from-absolute DATE)

Documentation

Persian year corresponding to the absolute DATE.

Source Code

;; Defined in /usr/src/emacs/lisp/calendar/cal-persia.el.gz
         day))))                        ; days so far this month

(defun calendar-persian-year-from-absolute (date)
  "Persian year corresponding to the absolute DATE."
  (let* ((d0                   ; prior days since start of 2820 cycles
          (- date (calendar-persian-to-absolute (list 1 1 -2345))))
         (n2820                         ; completed 2820-year cycles
          (floor d0 1029983))
         (d1                            ; prior days not in n2820
          (mod d0 1029983))
         (n768                          ; 768-year cycles not in n2820
          (floor d1 280506))
         (d2                         ; prior days not in n2820 or n768
          (mod d1 280506))
         (n1        ; years not in n2820 or n768
	  (floor (* 2820 (+ d2 366)) 1029983))
         (year (+ (* 2820 n2820)        ; complete 2820 year cycles
                  (* 768 n768)          ; complete 768 year cycles
                  ;; Remaining years.
                  (if (= d1 1029617)    ; last day of 2820 year cycle
                      (1- n1)
                    n1)
                  -2345)))              ; years before year 1
    (if (< year 1)
        (1- year)                       ; no year zero
      year)))