在javascript中比较日期的最简单方法是首先将其转换为Date对象，然后比较这些日期对象。

下面是一个具有三个功能的对象：

日期.比较（a，b）返回一个数字：-如果a<b，则为1如果a=b，则为0如果a>b，则为1如果a或b是非法日期，则为NaNdates.inRange（d，开始，结束）返回布尔值或NaN：如果d在开始和结束之间（含），则为true如果d在开始之前或结束之后，则为false。如果一个或多个日期是非法的，则为NaN。日期转换由其他函数用于将其输入转换为日期对象。输入可以是日期对象：输入按原样返回。数组：解释为[年，月，日]。注：月份为0-11。数字：解释为自1970年1月1日以来的毫秒数（时间戳）字符串：支持多种不同的格式，如“YYYY/MM/DD”、“MM/DD/YYYY”、“Jan 31 2009”等。对象：解释为具有年、月和日期属性的对象。注：月份为0-11。

.

// Source: http://stackoverflow.com/questions/497790
var dates = {
    convert:function(d) {
        // Converts the date in d to a date-object. The input can be:
        //   a date object: returned without modification
        //  an array      : Interpreted as [year,month,day]. NOTE: month is 0-11.
        //   a number     : Interpreted as number of milliseconds
        //                  since 1 Jan 1970 (a timestamp) 
        //   a string     : Any format supported by the javascript engine, like
        //                  "YYYY/MM/DD", "MM/DD/YYYY", "Jan 31 2009" etc.
        //  an object     : Interpreted as an object with year, month and date
        //                  attributes.  **NOTE** month is 0-11.
        return (
            d.constructor === Date ? d :
            d.constructor === Array ? new Date(d[0],d[1],d[2]) :
            d.constructor === Number ? new Date(d) :
            d.constructor === String ? new Date(d) :
            typeof d === "object" ? new Date(d.year,d.month,d.date) :
            NaN
        );
    },
    compare:function(a,b) {
        // Compare two dates (could be of any type supported by the convert
        // function above) and returns:
        //  -1 : if a < b
        //   0 : if a = b
        //   1 : if a > b
        // NaN : if a or b is an illegal date
        // NOTE: The code inside isFinite does an assignment (=).
        return (
            isFinite(a=this.convert(a).valueOf()) &&
            isFinite(b=this.convert(b).valueOf()) ?
            (a>b)-(a<b) :
            NaN
        );
    },
    inRange:function(d,start,end) {
        // Checks if date in d is between dates in start and end.
        // Returns a boolean or NaN:
        //    true  : if d is between start and end (inclusive)
        //    false : if d is before start or after end
        //    NaN   : if one or more of the dates is illegal.
        // NOTE: The code inside isFinite does an assignment (=).
       return (
            isFinite(d=this.convert(d).valueOf()) &&
            isFinite(start=this.convert(start).valueOf()) &&
            isFinite(end=this.convert(end).valueOf()) ?
            start <= d && d <= end :
            NaN
        );
    }
}

嗨，这是我比较日期的代码。在我的情况下，我正在检查是否允许选择过去的日期。

var myPickupDate = <pick up date> ;
var isPastPickupDateSelected = false;
var currentDate = new Date();

if(currentDate.getFullYear() <= myPickupDate.getFullYear()){
    if(currentDate.getMonth()+1 <= myPickupDate.getMonth()+1 || currentDate.getFullYear() < myPickupDate.getFullYear()){
                        if(currentDate.getDate() <= myPickupDate.getDate() || currentDate.getMonth()+1 < myPickupDate.getMonth()+1 || currentDate.getFullYear() < myPickupDate.getFullYear()){
                                            isPastPickupDateSelected = false;
                                            return;
                                        }
                    }
}
console.log("cannot select past pickup date");
isPastPickupDateSelected = true;

我通常将日期作为时间戳（数字）存储在数据库中。

当我需要比较时，我只需在这些时间戳或

将其转换为Date Object，然后根据需要与><进行比较。

请注意，==或==无法正常工作，除非变量是同一日期对象的引用。

首先将这些Date对象转换为时间戳（数字），然后比较它们的相等性。

日期到时间戳

var timestamp_1970 = new Date(0).getTime(); // 1970-01-01 00:00:00
var timestamp = new Date().getTime(); // Current Timestamp

截至日期的时间戳

var timestamp = 0; // 1970-01-01 00:00:00
var DateObject = new Date(timestamp);

function datesEqual(a, b)
{
   return (!(a>b || b>a))
}

If you are using **REACT OR REACT NATIVE**, use this and it will work (Working like charm)

如果两个日期相同，则返回TRUE，否则返回FALSE

const compareDate = (dateVal1, dateVal2) => {
        if (dateVal1.valueOf() === dateVal2.valueOf()){
            return true;
        }
        else { return false;}
    }

“一些”发布的代码的改进版本

/* Compare the current date against another date.
 *
 * @param b  {Date} the other date
 * @returns   -1 : if this < b
 *             0 : if this === b
 *             1 : if this > b
 *            NaN : if a or b is an illegal date
*/ 
Date.prototype.compare = function(b) {
  if (b.constructor !== Date) {
    throw "invalid_date";
  }

 return (isFinite(this.valueOf()) && isFinite(b.valueOf()) ? 
          (this>b)-(this<b) : NaN 
        );
};

用法：

  var a = new Date(2011, 1-1, 1);
  var b = new Date(2011, 1-1, 1);
  var c = new Date(2011, 1-1, 31);
  var d = new Date(2011, 1-1, 31);

  assertEquals( 0, a.compare(b));
  assertEquals( 0, b.compare(a));
  assertEquals(-1, a.compare(c));
  assertEquals( 1, c.compare(a));