import { Dayjs } from 'dayjs';
/**
 * Applies start of day (00:00:00.000) to a given date
 * @param date - Dayjs object
 * @returns Dayjs object with time set to 00:00:00.000
 */
export declare const applyStartOfDay: (date: Dayjs) => Dayjs;
/**
 * Applies end of day (23:59:59.999) to a given date
 * @param date - Dayjs object
 * @returns Dayjs object with time set to 23:59:59.999
 */
export declare const applyEndOfDay: (date: Dayjs) => Dayjs;
/**
 * Validates that a date range is valid (start is before or equal to end)
 * @param start - Start date (Dayjs or null)
 * @param end - End date (Dayjs or null)
 * @returns True if the range is valid, false otherwise
 */
export declare const validateDateRange: (start: Dayjs | null, end: Dayjs | null) => boolean;
/**
 * Converts a timestamp (milliseconds) to a Dayjs object
 * @param timestamp - Timestamp in milliseconds
 * @returns Dayjs object or null if timestamp is null or undefined
 */
export declare const timestampToDayjs: (timestamp: number | undefined | null) => Dayjs | null;