moment-msdate.js

'use strict';

(function(root, factory) {

	if (typeof define === 'function' && define.amd) {
		define(['moment-timezone'], factory);
	} else if (typeof module === 'object' && module.exports) {
		module.exports = factory(require('moment-timezone'));
	} else {
		factory(root.moment);
	}

}(this, (moment) => {

	/**
	* Constants
	*/
	const DAY_MILLISECONDS = 86400000;
	const MINUTE_MILLISECONDS = 60000;
	const MS_DAY_OFFSET = 25569;

	/**
	 * @description To JavaScript date from OLE Automation date
	 *
	 * @param msDate An OLE Automation date. Required.
	 * @param offsetToUtcInMinutes An offset from the msDate to UTC. If not supplied the offset from the system timezone will be used.
	 * @returns moment
	 */
	moment.fromOADate = function(msDate, offsetToUtcInMinutes) {
		let jO = new Date(((msDate - MS_DAY_OFFSET) * DAY_MILLISECONDS) + (msDate >= 0.0 ? 0.5 : -0.5));
		const tz = isNaN(parseInt(offsetToUtcInMinutes, 10)) ? jO.getTimezoneOffset() : offsetToUtcInMinutes;
		jO = new Date((((msDate - MS_DAY_OFFSET) + (tz / (60 * 24))) * DAY_MILLISECONDS) + (msDate >= 0.0 ? 0.5 : -0.5));
		return moment(jO);
	};

	/**
	 * To OLE Automation date from JavaScript date
	 *
	 * @param jsDate A JavaScript date object to convert to OA Date. Defaults to existing moment instance or new Date
	 * @returns Floating-point number, e.g., 41502.558798240745
	 */
	moment.fn.toOADate = function(jsDateInput) {
		const jsDate = jsDateInput || this._d || new Date();
		const timezoneOffset = jsDate.getTimezoneOffset() / (60 * 24);
		const msDateObj = (jsDate.getTime() / DAY_MILLISECONDS) + (MS_DAY_OFFSET - timezoneOffset);
		return msDateObj;
	};

	moment.updateLocale('en', {
		invalidDate: undefined
	});

	/**
	* Converts an OLE Automation date to a moment (baking in a timezone if one is supplied)
	* Returns a UTC Moment object instance
	*/
	moment.fromOADateWithZone = function(msDate, timeZone) {
		const jsTicks = (msDate - MS_DAY_OFFSET) * DAY_MILLISECONDS;
		const offset = moment.tz(timeZone).utcOffset() * MINUTE_MILLISECONDS;
		if (timeZone) {
			return moment.tz(jsTicks - offset, timeZone).utc();
		}
		return moment.utc(jsTicks);
	};

	/**
	* Converts a moment (with timezone) to an OLE Automation date in UTC
	* Returns an OLE Automation date in the form of a double
	*/
	moment.fn.toOADateWithZone = function() {
		const nMsDate = (this.valueOf() / DAY_MILLISECONDS) + MS_DAY_OFFSET;
		return nMsDate;
	};

	return moment;
}));