how to get a date from a previous date in seconds in nodejs

/*
Created by AroliS^
You are not allow to publish this code as your
All credits goes to me.
*/

//example code
timeFormat( old.timeStamp - new.timeStamp );

//function
  function timeFormat( ms )
    {
        var years
            , months
            , days
            , hours
            , mins
            , secs;

        secs    = parseInt( ms     * 0.001,     10 );
        mins    = parseInt( secs   * 0.0166667, 10 );
        hours   = parseInt( mins   * 0.0166667, 10 );
        days    = parseInt( hours  * 0.0416667, 10 );
        months  = parseInt( days   * 0.0328767, 10 );
        years   = parseInt( months * 0.0833334, 10 );

        years   = parseInt( (years%31536000), 10);
        months  = parseInt( (months%2678400), 10);
        days    = parseInt( (days%86400), 10);
        hours   = parseInt( (hours%3600), 10 );
        minutes = parseInt( (mins%60), 10 );
        secs    = parseInt( (secs%60), 10 );


        if ( years  != 0 ) return `${years} year(s)`;
        if ( months != 0 ) return `${months} month(s)`;
        if ( days   != 0 ) return `${days} day(s)`;
        if ( hours  != 0 ) return `${hours} hour(s)`;
        if ( mins   != 0 ) return `${mins} min(s)`;
        if ( secs   != 0 ) return `${secs} sec(s)`;
    }