@formatjs/intl-relativetimeformat

constructor(
    locales?: string | string[],
    options?: Intl.RelativeTimeFormatOptions
);

static localeData: Record<string, LocaleFieldsData>;

static polyfilled: boolean;

format: (value: number, unit: Intl.RelativeTimeFormatUnit) => string;

formatToParts: (
    value: number,
    unit: Intl.RelativeTimeFormatUnit
) => Intl.RelativeTimeFormatPart[];

resolvedOptions: () => Intl.ResolvedRelativeTimeFormatOptions;

static supportedLocalesOf: (
    locales: string | string[],
    options?: Pick<Intl.RelativeTimeFormatOptions, 'localeMatcher'>
) => string[];