fn:years-from-duration function

The fn:years-from-duration function returns the years component of a duration.

Syntax

duration-value: The duration value from which the years component is to be extracted.
duration-value is an empty sequence, or is a value that has one of the following types: xs:dayTimeDuration, xs:duration, or xs:yearMonthDuration.

Returned value

The return value depends on the type of duration-value:

If duration-value is of type xs:yearMonthDuration or is of type xs:duration, the returned value is of type xs:integer. The value is the years component of duration-value cast as xs:yearMonthDuration. The value is negative if duration-value is negative.
If duration-value is of type xs:dayTimeDuration, the returned value is of type xs:integer and is 0.
If duration-value is an empty sequence, the returned value is an empty sequence.

The years component of duration-value cast as xs:yearMonthDuration is the integer number of years determined by the total number of months of duration-value cast as xs:yearMonthDuration divided by 12.

Examples

The following function returns the years component of the duration -4 years, -11 months, and -320 days.

fn:years-from-duration(xs:duration("-P4Y11M320D"))

The returned value is -4.

The following function returns the years component of the duration 9 years and 13 months.

fn:years-from-duration(xs:yearMonthDuration("P9Y13M"))

The returned value is 10. When calculating the total number of years in the duration, 13 months is converted to 1 year and 1 month. The duration is equal to P10Y1M which has a years component of 10 years.