/**
 * Format a Date object to YYYY-MM-DD string
 */
export declare function formatDate(date: Date): string;
/**
 * Get default date range (last 12 months from today)
 */
export declare function getDefaultDateRange(): {
    start: string;
    end: string;
};
/**
 * Parse a date string and validate it
 */
export declare function parseDate(dateStr: string): Date | null;
/**
 * Validate date string format
 */
export declare function isValidDateString(dateStr: string): boolean;
/**
 * Format date range for display
 */
export declare function formatDateRange(start: string, end: string): string;
/**
 * Calculate the difference in days between two dates
 */
export declare function daysBetween(date1: Date, date2: Date): number;