import type { Weekday } from "./calendar/types";
/**
 * WHERE A KEY MOVES INSIDE A MONTH GRID — the WAI-ARIA grid model, as arithmetic
 * on dates rather than on cells.
 *
 * A cell index would have to know how many blanks a month starts with and how
 * many rows it has, and would stop at the month's edge; a date does not, so
 * ArrowDown on the last row lands in the next month and the caller simply shows
 * the month the returned date is in. `null` is "not a grid key" — the caller
 * must not preventDefault what it did not handle.
 */
export type CalendarGridKey = "ArrowLeft" | "ArrowRight" | "ArrowUp" | "ArrowDown" | "Home" | "End" | "PageUp" | "PageDown";
export declare function gridStep(key: string, from: Date, firstDayOfWeek: Weekday): Date | null;