Is BYYEARDAY useful enough ?
ByYearDay allows the user to enter days of the year to repeat separated by commas (1,2,…366,-366,-365…-1). Almost every real example can be represented in a more user friendly fashion using other ‘BY’s such as BYMONTH and BYMONTHDAY
An example: RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU;BYYEARDAY=72
Only leap years affect whether the 72nd day of the year is 31+28+13 = March 13 or 31+29+12 = March 12. It’s just not useful enough to schedule a meeting on “March 13, except March 12 if it’s a leap year” and that kind of use case can be worked around. (One special case might be to state that a RRULE that occured yearly on Feb 29 might automatically recur on Feb 28 if not a leap year). Without BYYEARDAY we’d see rules like “RRULE:FREQ=YEARLY; INTERVAL=1” and the date would be March 12 every year.
For this reason, at launch, the amr events plugin does not offer a BYYEARDAY entry option on the edit event screen. It will however read BYYEARDAY’s entered in ics files and apply the necessary recurrence rule and included in any calendar listing.
Does your group need BYYEARDAY ?
If your website needs to be able to offer entry of recurring dates using BYYEARDAY for it’s members, it will be easy to add. It is beingexcluded to avoid cluttering the screen unnecessarily.