javascript - 您如何获得JavaScript时间戳？(How do you get a timestamp in JavaScript?)

Question

How can I get a timestamp in JavaScript? (如何获取JavaScript时间戳？)

Something similar to Unix timestamp , that is, a single number that represents the current time and date. (与Unix时间戳类似，即代表当前时间和日期的单个数字。) Either as a number or a string. (可以是数字或字符串。)

  ask by pupeno translate from so

Answer 1

Short & Snazzy: (简短而时髦：)

+ new Date()

A unary operator like plus triggers the valueOf method in the Date object and it returns the timestamp (without any alteration). (像plus这样的一元运算符会触发Date对象中的valueOf方法，并返回时间戳（不做任何更改）。)

Details: (细节：)

On almost all current browsers you can use Date.now() to get the UTC timestamp in milliseconds ; (在几乎所有当前的浏览器上，您都可以使用Date.now()来获取UTC时间戳（以毫秒为单位） ；) a notable exception to this is IE8 and earlier (see compatibility table ). (IE8和更早版本是一个明显的例外（请参阅兼容性表 ）。)

You can easily make a shim for this, though: (不过，您可以轻松地对此进行填充：)

if (!Date.now) {
    Date.now = function() { return new Date().getTime(); }
}

To get the timestamp in seconds , you can use: (要获取以秒为单位的时间戳，可以使用：)

Math.floor(Date.now() / 1000)

Or alternatively you could use: (或者，您可以使用：)

Date.now() / 1000 | 0

Which should be slightly faster, but also less readable (also see this answer ). (这应该稍快一些，但可读性也要差一些（另请参见此答案 ）。)

I would recommend using Date.now() (with compatibility shim). (我建议使用Date.now() （具有兼容性垫片）。) It's slightly better because it's shorter & doesn't create a new Date object. (它稍微好一点，因为它更短并且不会创建新的Date对象。) However, if you don't want a shim & maximum compatibility, you could use the "old" method to get the timestamp in milliseconds : (但是，如果您不希望使用Shim和最大的兼容性，则可以使用“旧”方法来获取时间戳（以毫秒为单位） ：)

new Date().getTime()

Which you can then convert to seconds like this: (然后您可以将其转换为秒，如下所示：)

Math.round(new Date().getTime()/1000)

And you can also use the valueOf method which we showed above: (您还可以使用上面显示的valueOf方法：)

new Date().valueOf()

Timestamp in Milliseconds (时间戳（毫秒）)

 var timeStampInMs = window.performance && window.performance.now && window.performance.timing && window.performance.timing.navigationStart ? window.performance.now() + window.performance.timing.navigationStart : Date.now(); console.log(timeStampInMs, Date.now());