import type { TScheduleCadence } from './types/schedules';
/**
 * Compiles a cadence to the cron expression the engine fires from. Shared rather
 * than server-owned because the dialog previews the next runs, validates the
 * interval floor, and disables its own submit from these same functions: a second
 * client-side implementation would drift and either show run times the schedule
 * does not keep or accept a cadence the server then rejects.
 */
export declare function cadenceToCron(cadence: TScheduleCadence): string;
/**
 * Everything `cronCadenceSchema` will accept: exactly five fields, within the length
 * the schema stores, and actually matching at some point. croner accepts syntactically
 * valid patterns that can never match (`0 0 30 2 *`), and those would arm a schedule
 * that never fires. Validated with croner rather than a regex, because a regex would
 * accept patterns croner then rejects at fire time.
 *
 * A five-field expression that matches at all matches forever, which is what lets every
 * caller keep reading "no next occurrence" as "this cadence is unreadable".
 */
export declare function isValidCronExpression(expression: string, timezone?: string): boolean;
/**
 * The next occurrences the engine would fire. Server-side jitter (up to two
 * minutes) is deliberately not modelled: it is keyed off a schedule id that does
 * not exist yet at create time, and showing 9:01 for a 9:00 schedule reads as a bug.
 */
export declare function nextRunInstants(cadence: TScheduleCadence, timezone: string, count: number): Date[];
/**
 * Minimum minutes between occurrences, for the admin interval floor. `timezone` is
 * the schedule's own; passing it lets the cron branch measure a DST-compressed gap
 * instead of estimating one. The structured branches are zone-independent: their
 * formulas already carry the worst-case allowance.
 */
export declare function cadenceIntervalMinutes(cadence: TScheduleCadence, timezone?: string): number;