/**
 * Return whether `value1` and `value2` represent the same instant.
 *
 * - Uses Temporal.Instant.compare for equality check.
 * - Returns false if either input is invalid.
 *
 * @param value1 first UTC datetime string
 * @param value2 second UTC datetime string
 * @returns `true` if `value1` equals `value2`, otherwise `false`
 *
 * @example areUtcEqual("2024-03-17T14:30:45Z", "2024-03-17T14:30:45Z") // true
 * @example areUtcEqual("2024-03-17T14:30:45Z", "2024-03-17T14:30:44Z") // false
 * @example areUtcEqual("2024-03-17T14:30:45Z", "invalid") // false
 */
export declare function areUtcEqual(value1: string, value2: string): boolean;