title: method 'assign' not supported in IE, what to do
body: <p>I have a small /javascript,Babel script, that runs just fine in Chrome and Firefox browsers, but it fails in Internet Explorer 11.</p>
  
  <p>I hope somebody can help me.</p>
  
  <p>Here is my function:</p>
  
  <pre><code>getDaysWithEvents() {
      // Get all the days in this months calendar view
      // Sibling Months included
      const days = this.getCalendarDays();
  
      // Set Range Limits on calendar
      this.calendar.setStartDate(days[0]);
      this.calendar.setEndDate(days[days.length - 1]);
  
      // Iterate over each of the supplied events
      this.props.events.forEach((eventItem) =&gt; {
  
          const eventStart = this.getCalendarDayObject(eventItem.start);
          const eventEnd = this.getCalendarDayObject(eventItem.end);
          const eventMeta = this.getEventMeta(days, eventStart, eventEnd);
  
          if (eventMeta.isVisibleInView) {
              const eventLength = eventMeta.visibleEventLength;
              const eventSlotIndex = days[eventMeta.firstVisibleDayIndex].eventSlots.indexOf(false);
              let dayIndex = 0;
  
              // For each day in the event
              while (dayIndex &lt; eventLength) {
                  // Clone the event object so we acn add day specfic data
                  const eventData = Object.assign({}, eventItem);
  
                  if (dayIndex === 0) {
                       // Flag first day of event
                      eventData.isFirstDay = true;
                  }
  
                  if (dayIndex === eventLength - 1) {
                      // Flag last day of event
                      eventData.isLastDay = true;
                  }
  
                  if (!eventData.isFirstDay || !eventData.isLastDay) {
                      // Flag between day of event
                      eventData.isBetweenDay = true;
                  }
  
                  // Apply Event Data to the correct slot for that day
  
                  days[eventMeta.firstVisibleDayIndex + dayIndex].eventSlots[eventSlotIndex] = eventData;
  
                  // Move to next day of event
                  dayIndex++;
              }
          }
      });
  
      return days;
  }
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>SCRIPT438: The object does not support the property or method 'assign'
  </code></pre>
  
  <p>This line has Error: <code>var eventData = Object.assign({}, eventItem);</code></p>
  
  <p>Can I rewrite this line..?</p>
  
  <p>How to fix it ?</p>