import { Temporal } from "@js-temporal/polyfill";
import type { FractionalDigit } from "../../types/index.js";
export declare function startOrEndOfUtc(value: string, unit: Temporal.DateUnit | Temporal.TimeUnit, options: {
    weekStartsOn?: "monday" | "sunday";
    fractionalSecondDigits?: FractionalDigit;
}, isEnd: boolean): string;