@types/ms

ms: {
    (value: number, options?: { long: boolean }): string;
    (value: ms.StringValue): number;
};

type StringValue =
    | `${number}`
    | `${number}${UnitAnyCase}`
    | `${number} ${UnitAnyCase}`;

type Unit =
    | 'Years'
    | 'Year'
    | 'Yrs'
    | 'Yr'
    | 'Y'
    | 'Weeks'
    | 'Week'
    | 'W'
    | 'Days'
    | 'Day'
    | 'D'
    | 'Hours'
    | 'Hour'
    | 'Hrs'
    | 'Hr'
    | 'H'
    | 'Minutes'
    | 'Minute'
    | 'Mins'
    | 'Min'
    | 'M'
    | 'Seconds'
    | 'Second'
    | 'Secs'
    | 'Sec'
    | 's'
    | 'Milliseconds'
    | 'Millisecond'
    | 'Msecs'
    | 'Msec'
    | 'Ms';

type UnitAnyCase = Unit | Uppercase<Unit> | Lowercase<Unit>;