Format a time string with zero based hours and minutes in javascript

Question

This is what have tried:

partly pseudocode:

var hours = date1.getHours();
var minutes = date2.getMinutes();

if (hours.length == 1)
    hours = "0" + hours;

if (minutes.length == 1)
    minutes = "0" + minutes;

var time = hours + ':' + minutes;

Is there a smarter way like a formatted string function where I can say:

var minutes = date.getMinutes('mm');
var hours = date.getHours('hh');

so it adds the zeros automatically ?

possible duplicate of [Javascript add leading zeroes to date](http://stackoverflow.com/questions/3605214/javascript-add-leading-zeroes-to-date) — , May 22 '13 at 14:04

score 5 · Answer 1 · edited Jan 29 '14 at 23:03

5

Here is your code fixed since there is no length on an integer

var hours = date1.getHours();
var minutes = date2.getMinutes();

if (hours<10) hours = "0" + hours;
if (minutes<10) minutes = "0" + minutes;

var time = ""+ hours + ":" + minutes;

You do not need a framework and there is no shorter way to do this

This may be what you mean:

Live demo

function pad(num) {
  return ("0"+num).slice(-2)
}
var time = pad(date1.getHours())+":"+pad(date2.getMinutes());

edited Jan 29 '14 at 23:03

animuson

53,861
28
137
147

answered May 22 '13 at 14:07

mplungjan

169,008
28
173
236

3

Love the specific pad solution, "("0"+num).slice(-2)" – Xotic750 May 22 '13 at 14:17
It could be more general, but that would sort of defeat the purpose of keeping it short. For hours, minutes and seconds we only need max two chars – mplungjan May 22 '13 at 14:18

score 3 · Accepted Answer · edited May 23 '17 at 10:25

3

This functionality doesn't exist natively in javascript, you have to either add it yourself (as you have started to do), or, use a package.

edited May 23 '17 at 10:25

Community

1
1

answered May 22 '13 at 14:09

Jason

15,915
3
48
72

Love moments, a great and uncomplicated little date library. – Xotic750 May 22 '13 at 14:20
1

I did install moment.js now and got rid of 15 redundant lines of code replaced by 3 lines with better readability. I love moment from the very first moment... – Elisabeth May 23 '13 at 08:05

score 2 · Answer 3 · answered May 22 '13 at 14:06

2

Use DateJS and you will be able to use mm and hh to add the preceding zeros :)

https://code.google.com/p/datejs/wiki/FormatSpecifiers

answered May 22 '13 at 14:06

xShirase

11,975
4
53
85

Why the down vote? Some kind of conflict between Datejs and moment users? – xShirase May 22 '13 at 14:11
moment sounds much more l33t ;P – Elisabeth May 22 '13 at 14:27
1

Check this out : http://jsperf.com/underscore-date-vs-datejs/7 Quote : moment.js is lighter, and offers much faster parsing. On the other hand, date.js offers much faster formatting and manipulation. As the user is looking for formatting, I stick to my answer : DateJS rulez! – xShirase May 22 '13 at 14:30
1

its a shame that I have to use a library for such a common task... @xShirase If I would want speed I would not choose javascript ;-) – Elisabeth May 22 '13 at 19:06

score 1 · Answer 4 · answered May 22 '13 at 14:11

You can add a method to Number prototype

  Number.prototype.pad0 = function(length) {
    var result = this.toString();
    while(result.length<length) result = "0"+result;
    return result;
  }

Then you can get what you want

  var date = new Date();  
  console.log(date.getMinutes().pad0(2));
  console.log(date.getHours().pad0(2));

score 1 · Answer 5 · answered May 12 '14 at 19:41

Yet another way of doing it:

var d = new Date();
var t = [ d.getHours(), d.getMinutes(), d.getSeconds() ];

var s = t.map( function(z){return ('00'+z).slice(-2)} ).join(':');

console.log(s);

Time parts are put into an array. That array goes through map() where the numbers get leading zeros. The resulting array is then joined into a string with the ":" separator.

score 0 · Answer 6 · answered May 22 '13 at 14:11

0

Convert numbers to strings before you check the lengths:

var hours = String(date1.getHours());
var minutes = String(date2.getMinutes());

if (hours.length == 1)
    hours = "0" + hours;

if (minutes.length == 1)
    minutes = "0" + minutes;

var time = hours + ':' + minutes;

answered May 22 '13 at 14:11

kennebec

102,654
32
106
127

or just test they are less than 10 – mplungjan May 22 '13 at 15:21

Format a time string with zero based hours and minutes in javascript

6 Answers6