/**
 * Format a duration in milliseconds to a human-readable string.
 * Uses date-fns for durations >= 1 minute, custom formatting for shorter durations.
 *
 * @param ms - Duration in milliseconds
 * @returns Formatted duration string (e.g., "150ms", "2.50s", "3 minutes 45 seconds")
 */
export declare function formatDuration(ms: number): string;
/**
 * Format an ISO date string to a human-readable format
 *
 * @param isoString - ISO 8601 date string
 * @returns Formatted date string (e.g., "Dec 3, 2025 10:30 AM")
 */
export declare function formatDate(isoString: string | null | undefined): string;
/**
 * Calculate elapsed milliseconds between two ISO timestamps.
 * If completedAt is null/undefined, uses current time (for in-progress durations).
 */
export declare function elapsedMs(startedAt: string, completedAt?: string | null): number;
/**
 * Format a duration in milliseconds to a compact string that fits in narrow columns.
 * Always returns a short single-token string (e.g., "150ms", "7.56s", "24.2m", "1.3h").
 */
export declare function formatDurationCompact(ms: number): string;
/**
 * Format a duration between two ISO timestamps.
 *
 * @param startedAt - ISO 8601 start timestamp
 * @param completedAt - ISO 8601 end timestamp (or null if still running)
 * @returns Human-readable duration string (e.g., "5 seconds", "running")
 */
export declare function formatDurationFromTimestamps(startedAt: string, completedAt: string | null | undefined): string;