here is code:
date: new Date(2015,12,8)
and html:
<span>{{task.date | date:'MM/dd/yyyy'}}</span>
but angularJS displays this date like
01/08/2016
and I don't know why it's display +1 month
what I missed?
In JavaScript Date object the months are indexed starting with zero - i.e. Januray == 0.
In other words, you may want to change your date creation as follows:
date: new Date(2015,11,8)
please, notice that 11 stands for December
Months are indexed from 0. So your january month is 0 and Feb is 1 and so on. The reason why it starts with zero and not one, may be because it helps with indexing into arrays.
Related
I have an object with a date property. I set the date to 01 April 2000 and can see in the debugger that it is set properly to the same date. However when I do a getMonth() on the same date object it returns month as 3 ( March ) . Why is this happening. Does it have anything to do with UTC or Localization both of which i am not using ?
You need +1 for getMonth function
var month = date.getMonth() + 1
this is normal behavior. Months starts with Zero(i.e january is 0). thats why its giving 3 for april. use adding 1 with month to get exact month's digit value.
i guess, to help indexing javascript starts month with zero.
suppose an array of months in string form then we dont have to worry to fetch correct month from string.
I am creating a platform for recurring monthly orders.
I am using later.js for the recurrence. I have come across the following two cases and I am wondering if anybody has suggestions on how to better handle these (or if later.js handles them natively somehow):
later.parse.recur().on(31).dayOfMonth()
The date is the 31st of a given month. Current result is that is jumps months that end on the 30th. WORKAROUND: is to use last().dayOfMonth().
later.parse.recur().on(30).dayOfMonth()
later.parse.recur().on(31).dayOfMonth()
Month of February, ending on the 28th or 29th. How to handle if the date is 30th (or 31st). WORKAROUND: If date > 28th, add .and().on(59).dayOfYear()
Thanks!
I don't know the specifics of later.js, but apparently you can write something called a custom modifier: https://github.com/bunkat/later/blob/master/example/modifier.js
In addition to this, if you add a month to a javascript date (doesn't matter if the number becomes greater than 11/december), set the day of the month to the first then subtract 1 day, then you'll get the date of the last day in the originally given month. For example:
var a = new Date("2000-02-25");
var b = new Date(new Date(a.getFullYear(),a.getMonth()+1,1)-1);
console.log(b);
I am running this Javascript code on FireFox console:
> new Date(2015,01,29)
< Date 2015-03-01T03:00:00.000Z
I create a new date object with the date "2015-01-29" and the object instead saves the date "2015-03-01".
It also happens if I change the 'hour':
> new Date(2015,01,29,12)
< Date 2015-03-01T15:00:00.000Z
What's going on? I am completely lost on this.
How do I fix this 'bug'?
Thanks for helping!
Because the month-value starts with 0 (zero) new Date(2015,01,29) would be 29 of february which is not possible.
So for 2015-01-29 use 0 for the month parameter
new Date(2015,0,29)
MDN
new Date('2015,01,29') vs new Date(2015,01,29)
You are not using date input as string.
String format uses months as you would in real life: 01 - January.
Number format looks at months as indexes 0 - January.
I'm trying to validate a uk date using this code:
function ukdate(d) {
var p = new Date(d.split('/')[2], d.split('/')[1] -1, d.split('/')[0]);
if(p.toString() !== 'Invalid Date') {
return p;
}
}
http://jsfiddle.net/GE3xU/1/
so if I try ukdate('31/12/1981') it correctly returns "The Dec 31 1981". However if i try ukdate('12/31/1981') it returns "Tue Jul 12 1983".
Why is this happening? I'm expecting the second test to return invalid date because 31 is not a valid month.
JavaScript is converting your date for you.
In simple examples, you can get the last day of a given month by asking for the 0th day of the following month. Similarly, the "32nd of August" would be corrected to the 1st of September.
Months work similarly. The 13th month of a given year is the 1st month of the next. The 0th month of a year is December of the previous.
31 % 12 = 7, hence July, and floor(31/12) = 2 hence the year being shifted forward by two.
This is intended behaviour for JavaScript.
May I interest you in <input type="date" />? It uses whatever format is defined on the user's computer (ie. it is "locale-aware"), which is already excellent for user experience. On top of that, supporting browsers will render a calendar date picker, especially useful on phones too. Internally, the date is in "standard" YYYY-mm-dd format.
The month value is divided by 12 and added to the year, then the remainder is used as the actual month value.
See the spec
Let ym be y + floor(m /12).
Let mn be m modulo 12.
I am currently writing some sort of javascript based client calendar and observed some issues. All over the net, I can find code samples, where people use day overflows in the Date constructor.
i.e.
// get the first day of the next month
var myDate = new Date(someDate.getFullYear(),someDate.getMonth(),32);
myDate.setDate(1);
The general idea of this concept is, that since there is no month with 32 days, the constructor will create a date within the next month. I saw even codesample with negative overflows:
i.e.
// get the last day of the previous month
var myDate = new Date(someDate.getFullYear(),someDate.getMonth(),1);
myDate.setDate(-1);
Now while this seems to work in many cases, I finally found a contradiction:
// this prints "2012-12-30" expected was "2012-12-31"
var myDate = new Date(2013,0,1);
myDate.setDate(-1);
Further examination finally revealed that dates like
new Date(2013,0,23) or new Date(2013,0,16) combined with setDate(-1) all end up in "2012-12-31". Finally I observed that using -1 seems to subtract two days (for getting the expected result setDate(0) has to be used).
Is this a bug in the browser implementations or are the code samples spread accross the internet crap??
Furthermore, is this setDate with positive and negative overflow secure to be used and uniformly implemented by all major browsers?
From MDN:
If the parameter you specify is outside of the expected range, setDate attempts to update the date information in the Date object accordingly. For example, if you use 0 for dayValue, the date will be set to the last day of the previous month.
It's logical if you think about it: setDate(1) sets the date to the first of the month. To get the last day of the previous month, that is, the day before the first of this month, you subtract one from the argument and get 0. If you subtract two days (1 - 2) you get the second to last day (-1).
are [..] code samples spread accross the internet crap?
Yes. This is true at least 90% of the time.
At MDN they say:
If the parameter you specify is outside of the expected range, setDate
attempts to update the date information in the Date object
accordingly. For example, if you use 0 for dayValue, the date will be
set to the last day of the previous month.
So you're getting coherent results:
1 - Jan 1
0 - Dec 31
-1 - Dec 30
-2 - Dec 29
Edit: It may look counter-intuitive if you think of it as a mere relative value, such as PHP's strtotime() function:
strtotime('-1 day');
It's not the case ;-)