startOf/endOf("week") are not locale aware

[fuwaneko]

When I set week.dow to 1 and let's assume it's Saturday 14th April today and I say

moment().startOf("week")

It gives me today instead of Monday 8th April.

http://jsfiddle.net/zQx23/

[mlilley]

I concur:

// In Australia, weeks start on Monday (not Sunday)
moment.lang('en', { week: { dow: 1, doy: 4 } });
moment().startOf('week').format('dddd');      // --> "Sunday"  (expecting "Monday")
moment().endOf('week').format('dddd');       // --> "Saturday"  (expecting "Sunday")

Moment appears to be ignoring the attempted configuration change. See: http://jsfiddle.net/PPu8E/2/

It also seems to be ignoring the change when applied as part of the supplied moment/lang/en-gb.js configuration (which includes the above "week" config):

moment.lang('en-gb');
moment().startOf('week').format('dddd');      // --> "Sunday"  (expecting "Monday")
moment().endOf('week').format('dddd');       // --> "Saturday"  (expecting "Sunday")

and:

moment().lang('en-gb').startOf('week').format('dddd');    // --> "Sunday"  (expecting "Monday")

Australia subscribes to ISO 8601, via Australian standard AS ISO 8601-2007, which defines the first day of the week to be Monday. Not sure if there's a case for having an en-au.js language config also, or whether you would recommend we just use en-gb.

[fuwaneko]

I think the problem is in day() function which is not locale-aware. I changed it in my local copy of moment.js, but I'm not sure if it's the right thing to do. Also, weekdays, weekdaysShort and weekdaysMin must be changed in language options (maybe in Language.prototype) or date will be messed like "Sunday 8th April".

I'm actually really surprised that this issue was not mentioned earlier by someone.

[mlilley]

Thanks! I ran into the issue trying to get the sunday of last week (for any moment()), and wanted it to be the Sunday irrespective of timezone.

moment().substract('weeks', 1).endOf('week')   // saturday ... fail

Your comment helped me workaround the issue by pointing me towards the day() function, which I'd overlooked:

moment().subtract('weeks', 1).day(7) [.endOf('day')]    // last sunday, [23:59:59] ... win!

[fuwaneko]

There is actually a pull request for this bug, but it does not work properly. The correct solution was provided in comments to pull request.

[timrwood]

Related to #634 and #613.

This comment outlines my proposed fix, but I haven't had time to write it yet. #613 (comment)

[timrwood]

This is fixed via a58e5b7, it should go out in the 2.1.0 release. See #634 for the full discussion.

[MaestroJurko]

I updated from 2.0 to 2.1, tried 2.7 and this issue is still present.

moment.lang('en', {
    week: {
        dow: 1 // Monday is the first day of the week.
    }
});

moment().startOf('week').format('dddd'); // Sunday

I cannot update the library to much, the project is 1 year old.
??

[emamirazavi]

dow does not work correctly! I have problem too!!! my version is 2.8.4
I set it to 6 to start weeks with Sat but it starts with Mon!!! Any solution my experts?!

[algesten]

same here. 2.8.4

moment(Date.now()).lang('sv',{week:{dow:1}}).startOf('week').format('ddd')
...
"Sun"

[emamirazavi]

my problem was about bootstrap datepicker and it does not relate to moment

[kimmobrunfeldt]

I'm using moment 2.8.4 and setting locale works for me:

$ node
> var moment = require('moment');
undefined
> console.log('Version', moment.version);
Version 2.8.4
undefined
> moment.locale('en', {
>     week: {
>         dow: 1 // Monday is the first day of the week.
>     }
> });
'en'
> moment().startOf('week').format('dddd');
'Monday'
>

It also seems that .lang is now deprecated:

> moment.lang('en', {
>     week: {
>         dow: 1 // Monday is the first day of the week.
>     }
> });
Deprecation warning: moment.lang is deprecated. Use moment.locale instead.

[sahanDissanayake]

@kimmobrunfeldt
Guys this solution seems to break, the following code to get the current week number

moment().week() // NaN 

EDIT

You have to add doy: 6 as default to make it work

[uriklar]

@sahanDissanayake Could you please explain why you set doy to 6? The docs say it should be set to 4

[sahanDissanayake]

oh mate I'm not sure, At the time it seemed to get the job done which is to make Monday the starting day of the week, I have moved on to other projects now.

[sahanDissanayake]

@uriklar I got the 6 from here https://github.com/moment/moment/blob/develop/moment.js#L2540

[sahanDissanayake]

is this solved ??
Im using v2.13.0

I tried to do moment.weekdays() but still the start day is Sunday.. it should have been Monday

[RomainSF]

this is ridiculous, can someone fix this?

[fuwaneko]

@RomainSF @sahanDissanayake I think you should file separate bug for moment.weekdays() since startOf/endOf("week") work properly.

[offirpeer]

I am using version : 2.15.2 and

moment().subtract(1, 'weeks').startOf('week') return sunday , and when I change my ip to united states I still get sunday when I expect to get monday.
any solution for that?

[butterflyhug]

@offirpeer Moment supports a wide range of locales, but you will need to explicitly select the locale that is most appropriate for your application in a particular location. A bunch of folks use moment.locale(window.navigator.language) to autodetect an appropriate locale in most circumstances, but that's based on the locale settings of the user's computer and browser -- not their IP address.

Also, note that .startOf('week') is Sunday in the default U.S. locale -- U.S. calendars generally print Sunday as the first day of the week. If none of the built-in locale definitions will meet your needs, you can always create a custom locale (as described in the docs) and then select that for use on your site.

Please open a new issue or reach out on Gitter if you still have questions.

[efroim102]

@offirpeer Use 'isoweek' instead of 'week' if your week starts on Monday.

[seltix5]

Hello,
I found this problem too, in my case I wanted the startOf Day using moment-with-locales.min.js 2.21.0

var a = moment("2018-03-25T22:24:03+01:00");
a.format()
 // 2018-03-25T22:24:03+01:00

var b = a.startOf('day');
b.format()
 // 2018-03-25T00:00:00+00:00

after using "startOf" the timezone is set to zero.
I reported the same problem here : moment/moment-timezone#208

UPDATE : this was not a error! it is correct since there was the hour change at this date. Credits to @reinhrst.
moment/moment-timezone#208 (comment)