import toDate from "../toDate/index.js"; import requiredArgs from "../_lib/requiredArgs/index.js"; /** * @name isFirstDayOfMonth * @category Month Helpers * @summary Is the given date the first day of a month? * * @description * Is the given date the first day of a month? * * ### v2.0.0 breaking changes: * * - [Changes that are common for the whole library](https://github.com/date-fns/date-fns/blob/master/docs/upgradeGuide.md#Common-Changes). * * @param {Date|Number} date - the date to check * @returns {Boolean} the date is the first day of a month * @throws {TypeError} 1 argument required * * @example * // Is 1 September 2014 the first day of a month? * var result = isFirstDayOfMonth(new Date(2014, 8, 1)) * //=> true */ export default function isFirstDayOfMonth(dirtyDate) { requiredArgs(1, arguments); return toDate(dirtyDate).getDate() === 1; }