I think it will be great if this goes into worg? - Noorul
On Aug 19, 2010, at 1:52 AM, Paul Sexton <psex...@xnet.co.nz> wrote: > In org, timestamps can be in the usual angle-bracket format, > eg <2010-08-19 +2w>, or you can use lisp s-expressions. These are in the same > format as the s-expressions used in the 'diary'/'calendar' emacs packages. I > only discovered these recently but have been able to use them to schedule some > complex recurring items. I thought I would share the code here. > > 1. Recurring items with a limited number of occurrences > > For example, say you are taking night classes in Spanish. The class is every > Wednesday evening at 7pm, starting on 18 August, and runs for 8 weeks. AFAIK > Org's timestamps do not support limited occurrences of recurrent items -- you > have to schedule the item with infinite recurrences, then delete it when it > finishes. > > To schedule the Spanish classes, put the following in your .emacs: > > (defun diary-limited-cyclic (recurrences interval m d y) > "For use in emacs diary. Cyclic item with limited number of recurrences. > Occurs every INTERVAL days, starting on YYYY-MM-DD, for a total of > RECURRENCES occasions." > (let ((startdate (calendar-absolute-from-gregorian (list m d y))) > (today (calendar-absolute-from-gregorian date))) > (and (not (minusp (- today startdate))) > (zerop (% (- today startdate) interval)) > (< (floor (- today startdate) interval) recurrences)))) > > The item in the org file looks like this: > > > ** 19:00-21:00 Spanish lessons > <%%(diary-limited-cyclic 8 7 8 18 2010)> > > > 2. Public holiday that is "the nearest Monday to DATE" > > In New Zealand each regional capital has an "Anniversary Day". The date of > Auckland's anniversary day is "the nearest Monday to 29 January". > > Put this in your .emacs: > > (defun calendar-nearest-to (target-dayname target-day target-month) > "Recurring event that occurs in the nearest TARGET-DAYNAME to > the date TARGET-DAY, TARGET-MONTH each year." > (interactive) > (let* ((dayname (calendar-day-of-week date)) > (target-date (list target-month target-day (calendar-extract-year > date))) > (days-diff (abs (- (calendar-day-number date) > (calendar-day-number target-date))))) > (and (= dayname target-dayname) > (< days-diff 4)))) > > Now we can schedule Auckland Anniversary Day. The first argument, 1, means > Monday (days of the week are numbered starting with Sunday=0). > > > *** Auckland Anniversary Day > <%%(calendar-nearest-to 1 29 1)> > > > 3. Public holiday on "the 4th Monday in October". > > This does not require any additions to .emacs: > > > *** Labour Day (NZ) > <%%(diary-float 10 1 4)> > > > 4. Easter > > Easter's date moves around from year to year according to a complicated set of > criteria which I do not claim to understand. However the following code will > allow you to schedule recurring events relative to Easter sunday. > > Note: the function da-easter is from: > http://github.com/soren/elisp/blob/master/da-kalender.el > > Put the following in your .emacs: > > (defun da-easter (year) > "Calculate the date for Easter Sunday in YEAR. Returns the date in the > Gregorian calendar, ie (MM DD YY) format." > (let* ((century (1+ (/ year 100))) > (shifted-epact (% (+ 14 (* 11 (% year 19)) > (- (/ (* 3 century) 4)) > (/ (+ 5 (* 8 century)) 25) > (* 30 century)) > 30)) > (adjusted-epact (if (or (= shifted-epact 0) > (and (= shifted-epact 1) > (< 10 (% year 19)))) > (1+ shifted-epact) > shifted-epact)) > (paschal-moon (- (calendar-absolute-from-gregorian > (list 4 19 year)) > adjusted-epact))) > (calendar-dayname-on-or-before 0 (+ paschal-moon 7)))) > > > (defun da-easter-gregorian (year) > (calendar-gregorian-from-absolute (da-easter year))) > > (defun calendar-days-from-easter () > "When used in a diary sexp, this function will calculate how many days > are between the current date (DATE) and Easter Sunday." > (- (calendar-absolute-from-gregorian date) > (da-easter (calendar-extract-year date)))) > > Now we can schedule the public holidays associated with Easter as > recurring events. Good Friday is 2 days before "Easter", Easter Monday is one > day after. > > > *** Good Friday > <%%(= -2 (calendar-days-from-easter))> > > *** Easter Sunday > <%%(= 0 (calendar-days-from-easter))> > > *** Easter Monday > <%%(= 1 (calendar-days-from-easter))> > > > Paul > > > > _______________________________________________ > Emacs-orgmode mailing list > Please use `Reply All' to send replies to the list. > Emacs-orgmode@gnu.org > http://lists.gnu.org/mailman/listinfo/emacs-orgmode _______________________________________________ Emacs-orgmode mailing list Please use `Reply All' to send replies to the list. Emacs-orgmode@gnu.org http://lists.gnu.org/mailman/listinfo/emacs-orgmode
