如何以分钟为单位计算两个日期之间的时差

Question

I'm working with javascript and I have dates in this format "2016-04-15 1230" (yyyy-MM-dd HHmm) and I want to calculate the difference between these dates in minutes.

Example :

The difference between "2016-04-15 1230" and "2016-04-15 1210" is 20 minutes

Answer 1

moment.js is a good library for this sort of thing:

var firstTime = moment("2016-04-15 1230", "YYYY-MM-DD HHmm");
var secondTime = moment("2016-04-15 1210", "YYYY-MM-DD HHmm");

var difference = moment.duration(firstTime - secondTime);

console.log(difference.asMinutes()); // 20

Answer 2

First you need to get the Date representation of your date values.

/* Helper function that parses date string (format DD-YY-MM HH:mm) 
   to create a JS Date object*/
function getDateFromDateStr(dateStr) {
  var dateParts=dateStr.split(/\D/);
  return new Date(dateParts[0],dateParts[1],dateParts[2],dateParts[3],dateParts[4]);
}

...
... 
/*Use input string to create date objects*/
var str1= "2016-04-15 1210"; 
var str2= "2016-04-15 1230";

var len = str1.length;
var date1 = getDateFromDateStr(str1.slice(0,len-2) + ":" + str1.slice(len-2));
len = str2.length;
var date2 = getDateFromDateStr(str2.slice(0,len-2) + ":" + str2.slice(len-2));

Then you can simply get the difference in milliseconds by using simple subtraction and convert the result in minutes:

var differenceInMinutes = (date2 - date1)/(60*1000);

NOTE - Please keep in mind is that you should ONLY attempt arithmetic operations on Dates in UTC. Or if you can guarantee that they'll always be in the same time zone and won't have any DST.

Answer 3

a = new Date('2016-07-21 12:30'); b = new Date('2016-07-21 12:20');

console.log((ab)/60000);

prints 10.

Also see How to add 30 minutes to a JavaScript Date object?

Answer 4

Thanks @RobG for correcting me. Here is another go at it. I tried it with the time example given and changing both the minutes and hours of both times. I'm sure this isn't the fastest way but it is a homebrew.

var first = "2016-04-15 1230"

var second ="2016-04-15 1210"


var timeDiff = function(x, y) {

// Gets first hours and cuts it out
hrs1 = first.slice(11, 13);

// Gets second hours and cuts it out
hrs2 = second.slice(11, 13);

// Gets the minutes from first time and cuts it out
min1 = first.slice(13,15);

// Gets the minutes from second time and cuts it out
min2 = second.slice(13,15);

// Subtracts and puts the difference of minutes in minDiff variable
var minDiff = min1 - min2;

// Subtracts and puts the difference of hours in hrsDiff variable  
var hrsDiff = hrs1 - hrs2;

//  If it is negative, make it positive
if(minDiff <0){
minDiff *= -1;
}

if(hrsDiff < 0) {

  hrsDiff *= -1;

}

return ["Diff in hrs: " + hrsDiff, "Difference in Minutes: " + minDiff];

}

Returns: ["Diff in hrs: 0", "Difference in Minutes: 20"]

With times: "2016-04-15 1530", and "2016-04-15 1248",

Returns: ["Diff in hrs: 3", "Difference in Minutes: 18"]

Hope this was helpful.