Class DurationValue

packages/graph/src/TemporalTypes.ts:1050–1412

 * - P14D = 14 days (or P2W)
 */
export class DurationValue implements TemporalValue {
  public readonly temporalType = "duration";

  #months: number;
  #days: number;
  #seconds: number;
  #nanoseconds: number;

  public constructor(
    months: number = 0,
    days: number = 0,
    seconds: number = 0,
    nanoseconds: number = 0,
  ) {
    this.#months = months;
    this.#days = days;
    this.#seconds = seconds;
    this.#nanoseconds = nanoseconds;
  }

  /**
   * Create a DurationValue from an ISO 8601 duration string.
   * Format: P[n]Y[n]M[n]W[n]DT[n]H[n]M[n]S
   */
  public static fromString(iso: string): DurationValue | null {
    // Handle negative durations
    let isNegative = false;
    let str = iso;
    if (str.startsWith("-")) {
      isNegative = true;
      str = str.substring(1);
    }

    if (!str.startsWith("P")) return null;
    str = str.substring(1);

    let months = 0;
    let days = 0;
    let seconds = 0;
    let nanoseconds = 0;

    // Split by T to separate date and time parts
    const parts = str.split("T");
    const datePart = parts[0] || "";
    const timePart = parts[1] || "";

    // Parse date part (years, months, weeks, days)
    // Match patterns like "1Y", "2M", "1W", "3D"
    const datePattern = /(-?\d+(?:\.\d+)?)(Y|M|W|D)/g;
    let match: RegExpExecArray | null;
    while ((match = datePattern.exec(datePart)) !== null) {
      const value = parseFloat(match[1] ?? "0");
      const unit = match[2];
      switch (unit) {
        case "Y":
          months += value * 12;
          break;
        case "M":