The setUTCMonth() method of the Date object sets the month of the date (according to UTC). The month numbers start at 0. Ie, January is 0, February is 1, etc.

    
    const event = new Date('December 31, 1975 23:15:30 GMT-3:00');

    event.setUTCMonth(6);

    const month = event.getUTCMonth();
    console.log(month);
    // 6