How to parse a date string with microseconds

问题

I have some datetime string e.g.

"2017-10-29T02:54:03.125983+00:00"
"2017-10-29T02:09:22.1453833+00:00"

with 6 or 7 digital length milliseconds, how can I parse it to date object in d3 javascript language? I have tried

d3.timeParse("%Y-%m-%dT%H:%M:%S.%LZ"); 

but failed, it returns null

回答1:

What you have is not a long millisecond^✻: that is a microsecond.

There is a specifier in D3 for microseconds since D3 v4 (see here). To parse microseconds, use "f". According to the API:

%f - microseconds as a decimal number [000000, 999999].

Here is a demo with your string (don't look at the Stack snippet console, click "Run code snippet" and open your browser console to see the actual date):

var date = "2017-10-29T02:54:03.125983+00:00";
var parser = d3.timeParse("%Y-%m-%dT%H:%M:%S.%f%Z"); 
console.log(parser(date))

<script src="https://d3js.org/d3-time-format.v2.min.js"></script>

Three observations:

1. Contrary to what the own API says, "f" will not work with the default bundle. You have to reference the standalone time microlibrary (have a look at my demo above to see the URL). Lets prove it:

var date = "2017-10-29T02:09:22.145383+00:00";
var parser = d3.timeParse("%Y-%m-%dT%H:%M:%S.%f%Z"); 
console.log(parser(date))

<script src="https://d3js.org/d3.v4.min.js"></script>

2. Remove that "Z". It should be "%Z" instead. As the API says, "Note that the literal Z here is different from the time zone offset directive %Z";
3. There is no microsecond with 7 digits. It has to be 6 digits.

^✻ Title edited.

回答2:

You are trying to parse a date object which is incorrect, I think you want to format the date object.

Instead of:

d3.timeParse("%Y-%m-%dT%H:%M:%S.%LZ");

try this:

d3.timeFormat("%Y-%m-%dT%H:%M:%S.%LZ");

来源：https://stackoverflow.com/questions/47008978/how-to-parse-a-date-string-with-microseconds