/**
 * Convert an integer from 1 to 12 to a month.
 * @example
 * numberToMonth(1)   // => January
 * numberToMonth(12)  // => December
 */
export declare function numberToMonth(int: number): string;
/** A utility to store multiple timestamps for performance timing.
 * @example
 * const timer = new Timer()
 * timer.start('fetch starts')
 * timer.next('fetch resolved')
 * timer.end('awaiting done')
 */
export declare class Timer {
    /** The full state of the Timer object. */
    _log: any[];
    /** A list of Unix timestamps. */
    _times: () => any[];
    /** Add a midpoint to timer with optional label. */
    next: (label?: string) => number;
    /** Start timer with optional label. */
    start: (label?: string) => number;
    /** Add endpoint to timer with optional label. */
    end: (label?: string) => number;
    /** range :: () → [integer tF - t0] || NaN if fewer than 2 timestamps */
    range: (arr?: any[]) => number;
    /** delta :: () → [ integer list of velocities ] || [] if fewer than 2 timestamps */
    delta: ([head, ...tail]?: any[]) => any;
    /** Returns array of relative difference of time from start, with head as initial timestamp. */
    relative: ([head, ...tail]?: any[]) => any;
}