如果你通过 =比较两个日期= == ，比较两个日期对象的引用。表示相同日期的两个对象仍然是不同的对象。

If you compare two dates via ===, you compare the references of the two date objects. Two objects that represent the same date still are different objects.

相反，比较来自 Date.prototype.getTime（）$ c的时间戳$ c>：

function isDateInArray(needle, haystack) {
  for (var i = 0; i < haystack.length; i++) {
    if (needle.getTime() === haystack[i].getTime()) {
      return true;
    }
  }
  return false;
}

var dates = [
  new Date('October 1, 2016 12:00:00 GMT+0000'),
  new Date('October 2, 2016 12:00:00 GMT+0000'),
  new Date('October 3, 2016 12:00:00 GMT+0000'),
  new Date('October 2, 2016 12:00:00 GMT+0000')
];

var uniqueDates = [];
for (var i = 0; i < dates.length; i++) {
  if (!isDateInArray(dates[i], uniqueDates)) {
    uniqueDates.push(dates[i]);
  }
}

console.log(uniqueDates);

优化和错误处理取决于你。

Optimization and error handling is up to you.