Class DateValue

packages/graph/src/TemporalTypes.ts:44–181

 * - ordinalDay: Day of year (1-366)
 */
export class DateValue implements TemporalValue {
  public readonly temporalType = "date";

  #year: number;
  #month: number;
  #day: number;

  public constructor(year: number, month: number, day: number) {
    this.#year = year;
    this.#month = month;
    this.#day = day;
  }

  /**
   * Create a DateValue from an ISO date string (YYYY-MM-DD).
   */
  public static fromString(iso: string): DateValue | null {
    const match = iso.match(/^(\d{4})-(\d{2})-(\d{2})$/);
    if (!match || !match[1] || !match[2] || !match[3]) return null;
    const year = parseInt(match[1], 10);
    const month = parseInt(match[2], 10);
    const day = parseInt(match[3], 10);
    return new DateValue(year, month, day);
  }

  /**
   * Create a DateValue from a map of components.
   */
  public static fromMap(map: Record<string, unknown>): DateValue | null {
    const year = map.year;
    const month = map.month;
    const day = map.day;
    if (typeof year !== "number" || typeof month !== "number" || typeof day !== "number") {
      return null;
    }
    return new DateValue(year, month, day);
  }

  public get year(): number {
    return this.#year;
  }

  public get month(): number {
    return this.#month;
  }

  public get day(): number {
    return this.#day;
  }

  /**
   * Get the ISO week number (1-53).
   * Uses the ISO 8601 definition where week 1 is the week containing January 4th.
   */
  public get week(): number {
    const date = new Date(Date.UTC(this.#year, this.#month - 1, this.#day));
    // Set to nearest Thursday: current date + 4 - current day number (making Sunday=7)
    const dayNum = date.getUTCDay() || 7;