import type { Overflow, TimeDurationUnit } from "../../types/index.js";
/**
 * Return a PlainTime ISO string with `units` subtracted from `value`.
 *
 * - Validates `value`, `units`, and `amount` before performing the subtract.
 * - Returns "" for invalid inputs.
 *
 * `overflow` ("constrain" (default) | "reject") is accepted for API consistency with sibling
 * subtract functions, but PlainTime arithmetic always wraps around the clock (e.g. 01:00 - 2 hours
 * = 23:00) rather than producing an out-of-range value, so it has no observable effect here.
 *
 * @param value ISO PlainTime string
 * @param units Partial<Record<TimeDurationUnit, number>> object specifying units to subtract
 * @param options optional: overflow ("constrain" | "reject" — accepted but inert, see above)
 * @returns ISO PlainTime string after subtraction, or "" on invalid input
 *
 * @example subtractTime("14:30:00", { hours: 1 }) // "13:30:00"
 * @example subtractTime("invalid", { hours: 1 }) // ""
 */
export declare function subtractTime(value: string, units: Partial<Record<TimeDurationUnit, number>>, options?: {
    overflow?: Overflow;
}): string;