Javascript DateDiff

Question

我在使用DateDiff函数时遇到问题。我在试着弄清楚两个日期/时间之间的区别。我已经读过这篇文章(What's the best way to calculate date difference in Javascript)，我也看过这篇教程(http://www.javascriptkit.com/javatutors/datedifference.shtml)，但我似乎无法理解它。

这就是我想要的东西，但没有成功。谁能告诉我我在做什么，以及我如何简化这件事。似乎有点编码过度了……？

//Set the two dates
var currentTime = new Date();
var month = currentTime.getMonth() + 1;
var day = currentTime.getDate();
var year = currentTime.getFullYear();
var currDate = month + "/" + day + "/" + year;
var iniremDate = "8/10/2012";

//Show the dates subtracted
document.write('DateDiff is: ' + currDate - iniremDate);

//Try this function...
function DateDiff(date1, date2) {
    return date1.getTime() - date2.getTime();
}

//Print the results of DateDiff
document.write (DateDiff(iniremDate, currDate);

Answer 1

第一次尝试先做加法，然后做减法。您无论如何都不能减去字符串，因此生成的结果是NaN。

第二个trry没有结束)。除此之外，您还可以在字符串上调用getTime。你需要使用new Date(...).getTime()。请注意，在减去日期时，您将获得以毫秒为单位的结果。您可以通过删除完整的天/小时/等来格式化它。

Answer 2

好的，对于那些想要一个工作示例的人，这里有一个简单的DateDiff ex，它以负值(日期已经过去)或正值(日期即将到来)告诉date逐日不同。

编辑:我更新了这个脚本，所以它将为你做一些简单的工作，并将结果转换为a -10，在本例中，这意味着日期已经过去。为currDate和iniPastedDate输入您自己的日期，您就可以开始了！！

//Set the two dates
var currentTime   = new Date()
var currDate      = currentTime.getMonth() + 1 + "/" + currentTime.getDate() + "/" + currentTime.getFullYear() //Todays Date - implement your own date here.
var iniPastedDate = "8/7/2012" //PassedDate - Implement your own date here.

//currDate = 8/17/12 and iniPastedDate = 8/7/12

function DateDiff(date1, date2) {
    var datediff = date1.getTime() - date2.getTime(); //store the getTime diff - or +
    return (datediff / (24*60*60*1000)); //Convert values to -/+ days and return value      
}

//Write out the returning value should be using this example equal -10 which means 
//it has passed by ten days. If its positive the date is coming +10.    
document.write (DateDiff(new Date(iniPastedDate),new Date(currDate))); //Print the results...

Answer 3

function setDateWeek(setDay){
    var d = new Date();
    d.setDate(d.getDate() - setDay); // <-- add this
    var curr_date = d.getDate();
    var curr_month = d.getMonth() + 1;
    var curr_year = d.getFullYear();
    return curr_date + "-" + curr_month + "-" + curr_year;
}


setDateWeek(1);