import type { JsonValue } from '../../types.ts';
export declare const WINDOW_BACK_DAYS = 30;
export declare const WINDOW_AHEAD_DAYS = 90;
/**
 * Resolve an IANA zone name, falling back to UTC when unknown.
 *
 * A calendar can name a zone this platform's ICU data does not carry.
 * Failing the whole listing over it would let one bad calendar hide every
 * other one, so fall back and keep going.
 */
export declare function zone(tz: string): Intl.DateTimeFormat;
/** The instant at which a local calendar day begins. */
export declare function localMidnight(day: string, tz: string): number;
/** The `YYYY-MM-DD` a day-count offset lands on, in floating date space. */
export declare function shiftDay(day: string, days: number): string;
/** The local date an instant falls on, `YYYY-MM-DD`. */
export declare function localDate(instant: number, tz: string): string;
/**
 * The RFC3339 timeMin/timeMax pair covering one local day.
 *
 * Computed as consecutive local midnights rather than start + 24h: a local
 * day is 23 or 25 hours on the two DST transitions each year, and adding a
 * fixed day would drop or double an hour of events.
 */
export declare function dayBounds(day: string, tz: string): [string, string];
/** The RFC3339 pair for the default listing window around a day. */
export declare function windowBounds(today: string, tz: string): [string, string];
/**
 * Whether a string is a real calendar date, not merely date-shaped.
 *
 * `2026-02-30` matches the shape and is not a day; letting it through made
 * stat report a directory that every later call then failed on.
 */
export declare function validDay(day: string): boolean;
/** Whether an event time slot is a floating all-day date. */
export declare function isAllDay(slot: Record<string, JsonValue>): boolean;
/**
 * Resolve one event time slot to an absolute instant.
 *
 * A dateTime with no offset is a zoned event, not an error: Google requires
 * an offset unless the slot names its own zone. Reading it in the host zone
 * would silently move the event.
 */
export declare function slotInstant(slot: Record<string, JsonValue>, tz: string): number | null;
/**
 * The absolute [start, end) span of an event.
 *
 * An all-day event's `end.date` is exclusive, so a one-day event is
 * `start=D, end=D+1` and its span closes at the midnight opening the next
 * day. That is the same convention the instant carries, so no adjustment is
 * applied here.
 */
export declare function eventSpan(event: Record<string, JsonValue>, tz: string): [number, number] | null;
/**
 * Every local day an event's span touches.
 *
 * The end is exclusive, so an event closing exactly at local midnight does
 * not reach into the following day; a zero-length event still occupies the
 * day it starts on.
 */
export declare function daysCovered(span: [number, number], tz: string): string[];
/**
 * The `HHMM-HHMM` label for an event as seen on one local day.
 *
 * Times are clamped to the day, so an event running through it reads
 * `0000-2400` rather than repeating times that belong to another day.
 * `2400` is how an end at the next local midnight is spelled, since `0000`
 * there would sort before the start.
 */
export declare function clampedHhmm(span: [number, number], day: string, tz: string): string;
//# sourceMappingURL=day.d.ts.map