/**
 * Formats a date according to the provided format string.
 *
 * @param {Date} date - The date to format.
 * @param {string} format - The format string.
 * @returns {string} - The formatted date string.
 */
export declare function formatDate(date: Date, format: string): string;
/**
 * Adds a specified number of days to a date.
 *
 * @param {Date} date - The original date.
 * @param {number} days - The number of days to add.
 * @returns {Date} - The new date.
 */
export declare function addDays(date: Date, days: number): Date;
/**
 * Subtracts a specified number of days from a date.
 *
 * @param {Date} date - The original date.
 * @param {number} days - The number of days to subtract.
 * @returns {Date} - The new date.
 */
export declare function subtractDays(date: Date, days: number): Date;
/**
 * Adds a specified number of months to a date.
 *
 * @param {Date} date - The original date.
 * @param {number} months - The number of months to add.
 * @returns {Date} - The new date.
 */
export declare function addMonths(date: Date, months: number): Date;
/**
 * Subtracts a specified number of months from a date.
 *
 * @param {Date} date - The original date.
 * @param {number} months - The number of months to subtract.
 * @returns {Date} - The new date.
 */
export declare function subtractMonths(date: Date, months: number): Date;
/**
 * Adds a specified number of years to a date.
 *
 * @param {Date} date - The original date.
 * @param {number} years - The number of years to add.
 * @returns {Date} - The new date.
 */
export declare function addYears(date: Date, years: number): Date;
/**
 * Subtracts a specified number of years from a date.
 *
 * @param {Date} date - The original date.
 * @param {number} years - The number of years to subtract.
 * @returns {Date} - The new date.
 */
export declare function subtractYears(date: Date, years: number): Date;
/**
 * Adds a specified number of weeks to a date.
 *
 * @param date - The original date.
 * @param weeks - The number of weeks to add.
 * @returns The new date.
 */
export declare function addWeeks(date: Date, weeks: number): Date;
/**
 * Subtracts a specified number of weeks from a date.
 *
 * @param date - The original date.
 * @param weeks - The number of weeks to subtract.
 * @returns The new date.
 */
export declare function subtractWeeks(date: Date, weeks: number): Date;
/**
 * Adds a specified number of quarters to a date.
 *
 * @param date - The original date.
 * @param quarters - The number of quarters to add.
 * @returns The new date.
 */
export declare function addQuarters(date: Date, quarters: number): Date;
/**
 * Subtracts a specified number of quarters from a date.
 *
 * @param date - The original date.
 * @param quarters - The number of quarters to subtract.
 * @returns The new date.
 */
export declare function subtractQuarters(date: Date, quarters: number): Date;
/**
 * Returns the start of the day for the given date.
 *
 * @param {Date} date - The original date.
 * @returns {Date} - The start of the day.
 */
export declare function startOfDay(date: Date): Date;
/**
 * Returns the end of the day for the given date.
 *
 * @param {Date} date - The original date.
 * @returns {Date} - The end of the day.
 */
export declare function endOfDay(date: Date): Date;
/**
 * Returns the start of the week for the given date.
 *
 * @param {Date} date - The original date.
 * @param {number} startDayOfWeek - The day the week starts on (0 for Sunday, 1 for Monday, etc.).
 * @returns {Date} - The start of the week.
 */
export declare function startOfWeek(date: Date, startDayOfWeek?: number): Date;
/**
 * Returns the end of the week for the given date.
 *
 * @param {Date} date - The original date.
 * @param {number} startDayOfWeek - The day the week starts on (0 for Sunday, 1 for Monday, etc.).
 * @returns {Date} - The end of the week.
 */
export declare function endOfWeek(date: Date, startDayOfWeek?: number): Date;
/**
 * Returns the start of the month for the given date.
 *
 * @param {Date} date - The original date.
 * @returns {Date} - The start of the month.
 */
export declare function startOfMonth(date: Date): Date;
/**
 * Returns the end of the month for the given date.
 *
 * @param {Date} date - The original date.
 * @returns {Date} - The end of the month.
 */
export declare function endOfMonth(date: Date): Date;
/**
 * Returns the start of the year for the given date.
 *
 * @param {Date} date - The original date.
 * @returns {Date} - The start of the year.
 */
export declare function startOfYear(date: Date): Date;
/**
 * Returns the end of the year for the given date.
 *
 * @param {Date} date - The original date.
 * @returns {Date} - The end of the year.
 */
export declare function endOfYear(date: Date): Date;
/**
 * Checks if the given date is today.
 *
 * @param {Date} date - The date to check.
 * @returns {boolean} - True if the date is today, otherwise false.
 */
export declare function isToday(date: Date): boolean;
/**
 * Checks if the given date is tomorrow.
 *
 * @param {Date} date - The date to check.
 * @returns {boolean} - True if the date is tomorrow, otherwise false.
 */
export declare function isTomorrow(date: Date): boolean;
/**
 * Checks if the given date is yesterday.
 *
 * @param {Date} date - The date to check.
 * @returns {boolean} - True if the date is yesterday, otherwise false.
 */
export declare function isYesterday(date: Date): boolean;
/**
 * Calculates the difference in days between two dates.
 *
 * @param {Date} a - The first date.
 * @param {Date} b - The second date.
 * @returns {number} - The difference in days.
 */
export declare function dateDiffInDays(a: Date, b: Date): number;
/**
 * Calculates the difference in months between two dates.
 *
 * @param {Date} a - The first date.
 * @param {Date} b - The second date.
 * @returns {number} - The difference in months.
 */
export declare function dateDiffInMonths(a: Date, b: Date): number;
/**
 * Calculates the difference in years between two dates.
 *
 * @param {Date} a - The first date.
 * @param {Date} b - The second date.
 * @returns {number} - The difference in years.
 */
export declare function dateDiffInYears(a: Date, b: Date): number;
/**
 * Gets the number of days in a month.
 *
 * @param year - The year.
 * @param month - The month (0-based, e.g., January is 0, February is 1, etc.).
 * @returns The number of days in the month.
 */
export declare function getDaysInMonth(year: number, month: number): number;
/**
 * Checks if a year is a leap year.
 *
 * @param year - The year to check.
 * @returns True if the year is a leap year, false otherwise.
 */
export declare function isLeapYear(year: number): boolean;