title: NgbDatepicker multiple months displays wrong days (always starts on monday)
body: <p>I'm using NgbDatepicker (version 4.2.2) setting <code>displayMonths</code> = 2 but I'm getting the wrong days.</p>
  
  <p>i.e : November ends on Saturday 30, but the next date displayed is Monday 1 instead on Sunday 1.</p>
  
  <pre><code> &lt;section class="popover-body"&gt;
      &lt;!-- date picker--&gt;
      &lt;ngb-datepicker #dp (select)="onDateSelection($event)" [displayMonths]="2" [dayTemplate]="t" outsideDays="hidden"&gt;
      &lt;/ngb-datepicker&gt;
    &lt;/section&gt;
  
  
    &lt;ng-template #t let-date let-focused="focused"&gt;
      &lt;span class="custom-day" [class.focused]="focused" [class.range]="isRange(date)" [class.faded]="isHovered(date) || isInside(date)"
        (mouseenter)="hoveredDate = date" (mouseleave)="hoveredDate = null"&gt;
        {{ date.day }}
      &lt;/span&gt;
    &lt;/ng-template&gt;
  </code></pre>