> dayTimeDuration and yearMonthDuration as standard
XACML DataTypes
> were added fairly late in the XACML 1.0 process.
One of the
> primary motivating use-cases for the duration
DataTypes was being
> able to say things like "permit if current date
minus subject
> birthdate is greater than or equal to 21". These
expressions
> require some way to subtract dates.
Note that there already exist
dateTime-[add|subtract]-[dayTime|yearMonth]Duration
functions. This means that you can say:
today - (21 year duration) >= Subject's BDay
This yields the same data in a different way. I
don't know if this meets other needs for duration
functions, or if this changes the urgency for
getting these duration functions into 1.1.
That said, I think the duration functions being
proposed seem reasonable.
seth
