Merge branch 'master' of git.sv.gnu.org:/srv/git/emacs

[gnu-emacs] / lisp / calendar / holidays.el

diff --git a/lisp/calendar/holidays.el b/lisp/calendar/holidays.el
index d36764a74ce8568771073a1d964c8b70d15b69d9..d282d74392ad3f6e24e611748c32d9575de6e572 100644 (file)
--- a/lisp/calendar/holidays.el
+++ b/lisp/calendar/holidays.el
@@ -1,7 +1,7 @@
 ;;; holidays.el --- holiday functions for the calendar package
 
-;; Copyright (C) 1989-1990, 1992-1994, 1997, 2001-2014
-;;   Free Software Foundation, Inc.
+;; Copyright (C) 1989-1990, 1992-1994, 1997, 2001-2015 Free Software
+;; Foundation, Inc.
 
 ;; Author: Edward M. Reingold <reingold@cs.uiuc.edu>
 ;; Maintainer: Glenn Morris <rgm@gnu.org>
@@ -267,9 +267,9 @@ For example, to add Bastille Day, celebrated in France on July 14, add
      (holiday-fixed 7 14 \"Bastille Day\")
 
 to the list.  To add Hurricane Supplication Day, celebrated in the Virgin
-Islands on the fourth Monday in August, add
+Islands on the fourth Monday in July, add
 
-     (holiday-float 8 1 4 \"Hurricane Supplication Day\")
+     (holiday-float 7 1 4 \"Hurricane Supplication Day\")
 
 to the list (the last Monday would be specified with `-1' instead of `4').
 To add the last day of Hanukkah to the list, use
@@ -791,8 +791,16 @@ is non-nil)."
 ;; Prior call to calendar-julian-from-absolute will autoload cal-julian.
 (declare-function calendar-julian-to-absolute "cal-julian" (date))
 
-(defun holiday-greek-orthodox-easter ()
-  "Date of Easter according to the rule of the Council of Nicaea."
+(defun holiday-greek-orthodox-easter (&optional n string)
+  "Date of Nth day after Easter (named STRING), if visible in calendar window.
+It is calculated according to the rule of the Council of Nicaea.
+Negative values of N are interpreted as days before Easter.
+STRING is used purely for display purposes.  The return value has
+the form ((MONTH DAY YEAR) STRING), where the date is that of the
+Nth day before or after Easter.
+
+For backwards compatibility, if this function is called with no
+arguments, it returns the date of Pascha (Greek Orthodox Easter)."
   (let* ((m displayed-month)
          (y displayed-year)
          (julian-year (progn
@@ -808,11 +816,10 @@ is non-nil)."
          (paschal-moon      ; day after full moon on or after March 21
           (- (calendar-julian-to-absolute (list 4 19 julian-year))
              shifted-epact))
-         (nicaean-easter           ; Sunday following the Paschal moon
-          (calendar-gregorian-from-absolute
-           (calendar-dayname-on-or-before 0 (+ paschal-moon 7)))))
-    (if (calendar-date-is-visible-p nicaean-easter)
-        (list (list nicaean-easter "Pascha (Greek Orthodox Easter)")))))
+        (abs-easter (calendar-dayname-on-or-before 0 (+ paschal-moon 7)))
+        (greg (calendar-gregorian-from-absolute (+ abs-easter (or n 0)))))
+    (if (calendar-date-is-visible-p greg)
+       (list (list greg (or string "Pascha (Greek Orthodox Easter)"))))))
 
 (provide 'holidays)