import { DayValue } from 'zeed';
export type PeriodType = 'day' | 'week' | 'month' | 'year' | 'custom';
export declare const firstDayOfWeek: any;
export declare const today: number;
/**
 * Compute the start day of the week for a given day.
 *
 * Given a DayValue, this function returns the DayValue that corresponds to the
 * first day of the week containing that day. The first day of the week is
 * controlled by `firstDayOfWeek` (0 = Sunday, 1 = Monday, ...), matching
 * JavaScript's Date.getDay() indexing. An `offset` may be provided to move
 * the result by whole weeks: 0 returns the start of the current week,
 * 1 returns the start of the next week, -1 the start of the previous week, etc.
 *
 * @param {DayValue} [day] - The input day (defaults to today).
 * @param {number} [offset] - Number of weeks to shift the computed week start.
 * @param {number} [firstDayOfWeek] - Index of the week's first day (0 = Sunday).
 *
 * @returns {DayValue} The DayValue representing the first day of the (offset) week.
 *
 * @remarks
 * Internally converts the DayValue to a Date, computes the weekday delta
 * relative to `firstDayOfWeek`, and applies a day offset (offset * 7 + correction).
 * This relies on the project's helpers (dayToDate, dayOffset) and preserves the
 * project's DayValue representation.
 */
export declare function dayWeekStart(day?: number, offset?: number, firstDayOfWeek?: number): DayValue;
export declare function dayMaxToday(day: DayValue, maxToday?: boolean): DayValue;
export declare function dayRangeWeek(day?: number, offset?: number, firstDayOfWeek?: number, maxToday?: boolean): [DayValue, DayValue];
export declare function dayRangeMonth(day?: number, offset?: number, maxToday?: boolean): [DayValue, DayValue];
export declare function dayRangeYear(day?: number, offset?: number, maxToday?: boolean): [DayValue, DayValue];
export declare function dayRangePeriod(startDay: DayValue, endDay: DayValue, offset: number, periodType?: PeriodType): [DayValue, DayValue];