import type { DateTimeCycleField } from "../../types/index.js";
/**
 * Return true when `field` is a valid DateTimeCycleField (a valid DateCycleField or
 * TimeCycleField). Used by `cycleDateTime` and `cycleZoned`, which can cycle either kind of field.
 *
 * @param field candidate value of any type
 * @returns boolean indicating validity
 *
 * @example isValidDateTimeCycleField("year") // true
 * @example isValidDateTimeCycleField("hour") // true
 * @example isValidDateTimeCycleField("week") // false
 * @example isValidDateTimeCycleField("invalid") // false
 * @example isValidDateTimeCycleField(123) // false
 * @example isValidDateTimeCycleField(null) // false
 */
export declare function isValidDateTimeCycleField(field: unknown): field is DateTimeCycleField;