export type DeliveryWindow = {
    /**
     * Hour of day, 0-23. The picker exposes only even 2-hour buckets
     * (0, 2, … 22) in local time, but the stored UTC value may be any whole
     * hour once a non-even offset is applied.
     */
    hour: number;
    /** Day of week, 0 (Sunday) - 6 (Saturday). */
    day: number;
};
/** Even-hour buckets (0, 2, … 22) shown in the delivery-window picker in local-time mode. */
export declare const STANDARD_DELIVERY_HOUR_BUCKETS: number[];
/**
 * Compute the device's timezone offset, in whole hours, relative to UTC for a
 * given IANA timezone. A positive value means the local time is ahead of UTC
 * (e.g. `Asia/Tokyo` → +9); a negative value means behind (e.g.
 * `America/New_York` → -4 during EDT).
 *
 * Timezones with sub-hour offsets (e.g. `Asia/Kolkata` at +5:30) are rounded
 * to the nearest whole hour, since the delivery-window picker only supports
 * whole hours. This means the cron may fire up to ~30 minutes away from the
 * displayed bucket for those users, which is acceptable for this coarse
 * 2-hour-window UI.
 * @param timezone An IANA timezone string, e.g. `America/New_York`. When
 *   undefined (device timezone could not be detected), returns `null` so
 *   callers can fall back to displaying raw UTC values.
 * @param reference The instant at which to evaluate the offset. Defaults to
 *   now, so daylight-saving transitions are respected.
 * @returns The whole-hour offset from UTC, or `null` when no timezone is given
 *   or the timezone is invalid.
 */
export declare function getDeliveryWindowOffsetHours(timezone: string | undefined, reference?: Date): number | null;
/**
 * Convert a stored UTC delivery window to the equivalent local-time window for
 * display. The hour is snapped down to the nearest lower even bucket so the picker
 * always has a valid selected option, and the day wraps when crossing midnight.
 * @param utc The window as stored on the backend (interpreted as UTC).
 * @param offsetHours The local offset from UTC in whole hours.
 */
export declare function fromUtcDeliveryWindow(utc: DeliveryWindow, offsetHours: number): DeliveryWindow;
/**
 * Convert a local-time delivery window (as picked in the UI, always an even
 * bucket) back to the UTC window to persist on the backend. The result is exact
 * (not snapped) so the delivery time stays accurate even for odd offsets; the
 * stored UTC hour may therefore be odd.
 * @param local The window as displayed/picked in local time.
 * @param offsetHours The local offset from UTC in whole hours.
 */
export declare function toUtcDeliveryWindow(local: DeliveryWindow, offsetHours: number): DeliveryWindow;
/**
 * Convert a stored UTC window for display in the picker. When the device
 * timezone is unknown (`offsetHours === null`), returns the raw stored values
 * without snapping so day-only edits do not change an untouched hour.
 */
export declare function getDisplayDeliveryWindow(utc: DeliveryWindow, offsetHours: number | null): DeliveryWindow;
/**
 * Apply a partial edit from the picker and return the UTC window to persist.
 * In UTC-fallback mode, only fields present in `edit` are updated; the rest
 * are taken unchanged from `storedUtc`.
 */
export declare function applyDeliveryWindowEdit(storedUtc: DeliveryWindow, edit: Partial<DeliveryWindow>, offsetHours: number | null): DeliveryWindow;
/**
 * Hour values to render in the delivery-window `<select>`, so the control can
 * always represent the current setting.
 *
 * - **UTC fallback** (`utcFallback: true`): every whole hour 0–23, since the UI
 *   shows the raw stored UTC hour (which may be odd after prior saves).
 * - **Local-time mode**: the standard even 2-hour buckets, plus the current
 *   `displayHour` when it is not already listed (defensive; normally snapped to even).
 */
export declare function getDeliveryHourPickerHours(displayHour: number, utcFallback: boolean): number[];
//# sourceMappingURL=conversion.d.ts.map