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| author | Paul Eggert <eggert@cs.ucla.edu> | 2015-08-13 12:16:25 -0700 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2015-08-13 12:17:50 -0700 |
| commit | b532875a6021cd1715321dda932b187522840944 (patch) | |
| tree | 33b6c2d8b43dc68efe2463325262d55fca9ea988 /lisp/calendar/holidays.el | |
| parent | 57adf425f511b90153f128e7679b5f432df13fb5 (diff) | |
| download | emacs-b532875a6021cd1715321dda932b187522840944.tar.gz | |
Optional args for holiday-greek-orthodox-easter
* etc/NEWS: Document this.
* lisp/calendar/holidays.el (holiday-greek-orthodox-easter):
Add optional args N and STRING, mimicking the API and code of
‘holiday-easter-etc’. From suggestion by Foivos S. Zakkak (Bug#21256).
Diffstat (limited to 'lisp/calendar/holidays.el')
| -rw-r--r-- | lisp/calendar/holidays.el | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/lisp/calendar/holidays.el b/lisp/calendar/holidays.el index 8085c1cf119..6d7cea6b8c5 100644 --- a/lisp/calendar/holidays.el +++ b/lisp/calendar/holidays.el @@ -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) |