How to handle Date objects without been affected by timezone

/**
    * Returns timestamp of passed date
    * by adding, difference of your localTimeZoneUtcOffset and organizationTimeZoneUtcOffset in date
    * @param date date object
    */

    static getTimeStamp(date?: Date): number {
        let result;
        let timeStamp;
        if (this._timeZone) {
            const currentMoment = moment();
            const localOffset = currentMoment.utcOffset();
            const convertedMoment = moment().tz(this._timeZone);
            const timeZoneOffset = convertedMoment.utcOffset();
            const diffInMinutes = localOffset - timeZoneOffset;
            if (date) {
                result = addMinutes(date, diffInMinutes);
            } else {
                result = addMinutes(new Date(), diffInMinutes);
            }
            timeStamp = result.getTime();
        } else {
            if (date) {
                timeStamp = date.getTime();
            } else {
                timeStamp = new Date().getTime();
            }
        }
        return timeStamp;
    }

    /**
     * Returns Date Object after converting your passed timestamp into the organization's timezone
     * @param timeStamp Timestamp
     * @param dateFormat Format of returned date object
     */
    static getDateUsingTimeStamp(timeStamp: number, dateFormat?: string): Date {
        const defaultFormat = 'MM/DD/YYYY HH:mm:ss';
        let date = '';
        if (this.timezone) {
            if (dateFormat) {
                date = moment(timeStamp).tz(this._timeZone).format(dateFormat);
            } else {
                date = moment(timeStamp).tz(this._timeZone).format(defaultFormat);
            }
        } else {
            date = format(timeStamp, 'MM/DD/YYYY HH:mm:ss');
        }
        const dateObj = new Date(date);
        return dateObj;
    }