/**
 * 时间单位字符串名称常量对象
 */
export declare const TimeUnit: {
    readonly millisecond: "millisecond";
    readonly second: "second";
    readonly minute: "minute";
    readonly hour: "hour";
    readonly day: "day";
};
/**
 * 时间单位类型
 */
export type TimeUnitType = typeof TimeUnit[keyof typeof TimeUnit];
/**
 * 时间单位转换
 *
 * @param {number} time 时间值
 * @param {TimeUnit} fromUnit 源单位
 * @param {TimeUnit} toUnit 目标单位，默认为秒
 * @returns {number} 目标单位的时间值
 */
export declare const convert: (time: number, fromUnit: TimeUnitType, toUnit?: TimeUnitType) => number;