@progress/kendo-date-math
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Kendo UI typescript package exporting functions for Date manipulations
31 lines (30 loc) • 1.27 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.addMonths = void 0;
var adjust_dst_1 = require("./adjust-dst");
var clone_date_1 = require("./clone-date");
var last_day_of_month_1 = require("./last-day-of-month");
var MONTHS_LENGTH = 12;
var normalize = function (date, expectedMonth) { return (date.getMonth() !== expectedMonth ? (0, last_day_of_month_1.lastDayOfMonth)((0, exports.addMonths)(date, -1)) : date //tslint:disable-line:no-use-before-declare
); };
/**
* A function that adds and subtracts months from a `Date` object.
*
* @param date - The initial date value.
* @param offset - The number of months to add or subtract from the date.
* @returns - A new `Date` instance.
*
* @example
* ```ts-no-run
* addMonths(new Date(2016, 5, 1), 5); // 2016-11-1
* addMonths(new Date(2016, 5, 1), -5); // 2015-1-1
* ```
*/
var addMonths = function (date, offset) {
var newDate = (0, clone_date_1.cloneDate)(date);
var diff = (newDate.getMonth() + offset) % MONTHS_LENGTH;
var expectedMonth = (MONTHS_LENGTH + diff) % MONTHS_LENGTH;
newDate.setMonth(newDate.getMonth() + offset);
return normalize((0, adjust_dst_1.adjustDST)(newDate, date.getHours()), expectedMonth);
};
exports.addMonths = addMonths;