Convert a string (in date format) to datetime using Javascript

问题

In BIRT, i have a column containing a datetime stored as a string. I need to convert these string to datetime format and put the result in another column using Javascript. The string is the form of: for example: Fri 21 Feb 2014, 09:40 AM.

Hence this when converted to a datetime format and exported to excel, the column should be treat as a date. Can any one of you help me to do it?

Cheers,

回答1:

Other answers do not take into consideration this question is in a BIRT context.

Create a computed column in your dataset, with "Date time" as datatype
Enter as expression:

new Date(row["myDateStringField"]);

Where "myDateStringField" is your DateTime column in a String format. Then use this computed column in your report instead of the String column.

That's it!

回答2:

Checkout momentjs!

You can parse your time of any format like

moment("12-25-1995", "MM-DD-YYYY");

In your case, you don't even have to specify the format. It automatically recognizes it.

And you can output ISO format or convert it to a Javascript Date object.

回答3:

This is extremely easy to do with javascript. The following code will make a date in a format that Excel will recognize as a date.

http://jsfiddle.net/bbankes/d7SwQ/

var dateString = 'Fri 21 Feb 2014, 09:40 AM';
var date = new Date(dateString);
var yr = date.getFullYear();
var mo = date.getMonth() + 1;
var day = date.getDate();

var hours = date.getHours();
var hr = hours < 10 ? '0' + hours : hours;

var minutes = date.getMinutes();
var min = (minutes < 10) ? '0' + minutes : minutes;

var seconds = date.getSeconds();
var sec = (seconds < 10) ? '0' + seconds : seconds;

var newDateString = yr + '-' + mo  + '-' + day;
var newTimeString = hr + ':' + min + ':' + sec;

var excelDateString = newDateString + ' ' + newTimeString;

回答4:

If you just want to reformat 'Fri 21 Feb 2014, 09:04 AM' as '2014-02-21 09:04', then the following will do:

function stringToTimestamp(s) {
  var t = s.match(/[\d\w]+/g);
  var months = {jan:'01',feb:'02',mar:'03',apr:'04',may:'05',jun:'06',
                jul:'07',aug:'08',sep:'09',oct:'10',nov:'11',dec:'12'};
  function pad(n){return (n<10?'0':'') + +n;}
  var hrs = t[4] % 12;
  hrs += /pm$/i.test(t[6])? 12 : 0;

  return t[3] + '-' + months[t[2].toLowerCase()] + '-' + pad(t[1]) + ' ' +
         pad(hrs) + ':' + pad(t[5]);
}

console.log(stringToTimestamp('Fri 21 Feb 2014, 09:04 AM')); // 2014-02-21 09:04

回答5:

use the ISO format: YYYY-MM-DDTHH:MM:SS or YYYY-MM-DD

new Date('2011-04-11T11:51:00');

new Date('2011-04-11');

来源：https://stackoverflow.com/questions/22446445/convert-a-string-in-date-format-to-datetime-using-javascript

标签

javascript

datetime

birt