DURATION function consumes a STRING representing an ISO 8601 duration and pushes back a LONG duration in platform time unit.
The ISO 8601 duration can be expessed as
xmilliseconds, independent of platform time unit Each of these values can be either positive or negative. Each value/unit couple can be omitted if the value is zero but at least one value/couple should be defined.
If the consumed ISO 8601 duration has micro or nanoseconds precision, these digits will be ignored.