Excellent time stamp function

timestamp.js

function getNow( off ) {
    let date = new Date();
    date.setTime( date.getTime() + ( 3600000 * off || 0 ) );
    let y  = date.getFullYear(),
        mo = date.getMonth() + 1,
        d  = date.getDate(),
        h  = date.getHours(),
        m  = date.getMinutes(),
        s  = date.getSeconds(),
        mm = date.getMilliseconds();

    mo = ( mo < 10 ? '0' : '' ) + mo;
    d  = ( d  < 10 ? '0' : '' ) + d;
    h  = ( h  < 10 ? '0' : '' ) + h;
    m  = ( m  < 10 ? '0' : '' ) + m;
    s  = ( s  < 10 ? '0' : '' ) + s;

    return y + mo + d + h + m + s + mm;
}