The negated() method of Temporal.Duration instances returns a new Temporal.Duration object with the negated value of this duration (all fields keep the same magnitude, but sign becomes reversed).
negated()None.
A new Temporal.Duration object, where all fields have the same magnitude as this duration, but the sign is reversed (positive fields become negative, and vice versa).
const d1 = Temporal.Duration.from({ hours: 1, minutes: 30 });
const d2 = Temporal.Duration.from({ hours: -1, minutes: -30 });
console.log(d1.negated().toString()); // "-PT1H30M"
console.log(d2.negated().toString()); // "PT1H30M"