getTime < Date < JavaScript

The getTime() method of the Date object returns the number of milliseconds for the date since the epoch, which is midnight at the beginning of January 1, 1970, UTC.

    
    const event = new Date('July 20, 2020 21:36:00');

    const epochSeconds = event.getTime();

    console.log(epochSeconds);
    // 1595295360000