在Javascript中，如何将日期对象转换为纪元时间戳？

Question

Wed, 07 Dec 2011 15:31:11 GMT

如果我有该日期对象，如何将其转换为unix时间戳（自纪元以来的秒数）？

Answer 1

var unixTimeStamp = (new Date('Wed, 07 Dec 2011 15:31:11 GMT')).getTime() / 1000;

Answer 2

You could use

var dateString = "Wed, 07 Dec 2011 15:31:11 GMT";
var mSecondsSinceEpoch = Date(dateString).getTime(); 

which returns the UNIX Epoch time in milliseconds. You can leave 'dateString' empty to take the current time. However, when a Date object is cast to a number, it will also return the above. Thus

var mSecondsSinceEpoch = +Date(dateString) // milliseconds

or

var secondsSinceEpoch = (Date(dateString) / 1000) // seconds

also works! See https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Date for more information on the Javascript Date object.

Answer 3

You can convert into a timestamp by coercing into a number, eg +date . However, this will return the amount of milliseconds.

To get the amount of seconds since epoch, you would need divide by 1000. Since dividing already involves numbers, you can eliminate the + :

Math.floor(date / 1000);   // 1000 ms = 1s