Re: [HC Evolution] Review of Calendar docs

[Ali Abdin <aliabdin aucegypt edu>]

> Ali Abdin writes:
>  > proclamation of the new moon by religious authorities. Consequently,
the
>  > dates given  by the Lisp function here can be in error by a day or two
from
>  > what will actually be observed in various parts of the Islamic world;
this
>  > is unavoidable.
>
> One wonders how users of the Islamic calendar plan a month long
> vacation :)

To be honest. Everyone uses the Gregorian calendar. Some people like
newspapers provide both :)

But there are some islamic-only things. For example - the whole month of
Ramadan has fasting and stuff and productivity goes waaay down (class/work
days/hours are reduced) and its basically a month full of 'traditional
stuff' (the simplest way to describe it (otherwise i'd be rambling on)). If
you look at the URL jwz provided (calendar.pas) it also lists a set of
Islamic-only vacations (such as Islamic new year, birth of the prophet) -
These are considered 'vacations' in Islamic countries so need to be taken
into account. (i.e. These dates occur on <X> islamic date regardless of
Gregorian -> Islamic conversion).

Its a difficult problem to explain but basically - it is a problem iof
setting an "appointment" in Islamic or Gregorian - you will have problems
deciding wether it is a "fixed" date or a "rolling" date. the easiest way
to handle this is to provide the user with a 'choice' - but then this needs
some sort of 'property' set on the event that you saved.