[Data-modeling] Representing complex dates

[Kirrily Robert]

On 15/11/2009, at 9:10 AM, Christopher R. Maden wrote:

> Paul Mackay wrote:
>> Thinking about how to record farmer's market vendors attendance  
>> dates, I
>> have a couple of questions:
>>
>> How to represent something like the "1st Saturday of May"? Day of  
>> Year is
>> too specific - it will change every year.
>
> I think Day of Year is exactly the thing.  Check out Easter, <URL:
> http://www.freebase.com/view/en/easter >.  Its day of year is First
> Sunday after the first full moon on or after March 21, <URL:
> http://www.freebase.com/view/guid/9202a8c04000641f8000000004f3fe29 >.

Just to be randomly pedantic and complicate matters, I believe that  
Eastern Orthodox churches calculate the date of Easter differently.   
The day of year property is non-unique, but there's no good way to say  
that the two values are exclusive.  Hmm.

K.

-- 
Kirrily Robert
Freebase Community Director
kirrily at metaweb.com