Hi Jason
This is quite a tricky requirement and there different approaches
which might work. My gut instinct is to have a single “internal”
timebase to the system and to deal with different calendaring
requirements on the aggregation, presentation and output side. So for
example a datavalue persisted with period 2010-Q1 would always refer
to Jan-Mar for that year, But in a report requiring USGOV-FY (please
don’t just say fiscal year - all countries have a fiscal year and they
don’t all run from Sep-Oct! Ah, I see Samuel has already come in on
this.) that same period would be presented (and aggregated) as
2010-Q2. There would be some complexities to solve here, but would
have the benefit that, at least internally, a time period is always a
comparable time period.
If we are going to mess around creating (yet more) custom period types
then one way might be to add an attribute to the period class
indicating the preferred calendar type to be used in aggregation and
reporting. So any period eg 2007 or 200-7-Q1 or 2007-01 would be
qualified by a calendar type (in most cases ISO8601 but also possibly
USGOV-FY). This is the approach finally agreed to in SDMX-HD, for
example though I haven’t seen how the IMR has implemented this. We
could also be less grand and just call the attribute an offset rather
than a calendar type, but there may be some requirements which go
beyond a simple 3 month offset. US week numbers for example 
Cheers
Bob
On 23 February 2011 06:11, Jason Pickering jason.p.pickering@gmail.com wrote:
Hi there. I was wondering if it would be possible to implement the fiscal
year period type? This meay have come up before, but it seems we may need it
soon.
FY 2010 runs from October 1st 2009 through September 30th 2010.
FY 2011 is from October 1st 2010 through September 30th 2011.
FY 2012 is from October 1st 2011 through September 30th 2012.
I think it would look something like this…perhaps…
private Period createPeriod( Calendar cal )
{
cal.set( Calendar.YEAR, cal.get( Calendar.YEAR ) + cal.get(
Calendar.MONTH ) % 10 );
cal.set( Calendar.MONTH, Calendar.OCTOBER );
cal.set( Calendar.DATE, 1 );
Date startDate = cal.getTime();
cal.add( Calendar.YEAR, 1 );
cal.set( Calendar.DAY_OF_YEAR, cal.get( Calendar.DAY_OF_YEAR ) - 1
);
return new Period( this, startDate, cal.getTime() );
}
What I am not sure about is all the rest of the methods which need to be in
the API, as well as the aggregation engine. Data will be entered in our case
quarterly, but needs to be aggregated to fiscal years.
Regards.
Jason
–
Jason P. Pickering
email: jason.p.pickering@gmail.com
tel:+260974901293