javascript - run a function at midnight of a given date - javascript

I need to run a JS function at midnight of a given date. Is that something possible with JS, mine is a node app and i was looking at the laterJS library but not sure how exactly i can use the recurse function from laterJS library for this need. It would be nice to use laterJS lib for this requirement as opposed to using something like node scheduler.
Please share any thoughts/ideas.
With this question i'm particularly looking to use a library that can do this like laterJS and not a CRON kind of thing that node scheduler provides.
The value of given date is completely dynamic and it could be any date in MM/DD/YYYY format so fundamentally i cannot hard code the value in later.parse.text as 25th day of the month etc.. but i can hard code the time as 11:59 pm, given the fact that the date is dynamic in MM/DD/YYYY format can i use later.parse.text('at 11:59 pm on the "+DD+"th day of "+MM+" in "+YYYY+"'); something like this...
So tried some thing like this, Constructing a later.parse.recur() to run on a specific day/month/year/time but not sure how to handle the time.. Any help?

May be Cron expression section of Later.js is what you are looking at. It is meant for exactly this sort of thing.
You can pick the relevant one from below -
If you want on a specific day of the month, the expression will be something like
var complexSched = later.parse.recur()
.on(15).dayOfMonth().onWeekday().on(2).hour()
If it is a repeating schedule, it will be something like
var textSched = later.parse.text('at 10:15am every weekday');
A cron expression will be something like this-
var cronSched = later.parse.cron('0 0/5 14,18 * * ?');

Related

Converting JavaScript date to JSON/.net date format

I have a regular date i.e.:
date= 03-12-2014
I need to convert it to JSON or .Net date format. Like this:
"\/Date(1283219926108)\/"
I can see a lot of posts that go from JSON date to regular date but not backward. Please let me know how to do it. I am hoping for some easy JavaScript way to do it.
Do you know/Have you tried (new Date).getTime()
That's the most easiest "cross-browser" solution I know of ...
In your situation something like:
(new Date(date)).getTime()
It's a little bit vague to see what the difference is between .net- and javascript code.
Can you point it out more clearly?
Take a look at this little jQuery file. https://gist.github.com/gigi81/1868478
It does date parsing for .NET.

Moment.js 2 different date strings when i parse using moment gives same value

I am parsing 2 different date strings
var d1 = '2014-02-01T00:00:00.000+0530'
var d2 = '2014-02-23T00:00:00.000+0530'
when i parse them using moment
alert(moment(d1, 'YYYY-MM-dd"T"HH:mm:ss.fffffff"Z"').toDate());
alert(moment(d2, 'YYYY-MM-dd"T"HH:mm:ss.fffffff"Z"').toDate());
both of them print Sat Feb 1 2014 xxxxx
what is wrong with it??
here is the link to the fiddle i created
jsfiddle
I think your moment formatting string is causing you the problem. If I remove this, the dates do not print as the same.
http://jsfiddle.net/K5ub8/7/
EDIT: The specific issue is you are using dd for day, instead of DD. http://momentjs.com/docs/#/parsing/string-format/
Here is your fiddle fixed:
http://jsfiddle.net/K5ub8/9/
However, I am not 100% sure about the fractional seconds, I believe it is SSS instead of fffffff but I would test this if you need to cater for fractional seconds.
I should mention that if you are converting it back into a JavaScript date object anyway with toDate(), then you don't really need the moment formatting parameter as the date will be formatted in JSON Date format.
I would question why you would want to generate a moment formatted date, and then convert it back to JavaScript, a normal practice might be to receive a date in JavaScript format, then create a moment object which you can use to perform calculations and display in a nice user friendly way.
Simple answer: your format was off a bit.
http://jsfiddle.net/K5ub8/8/
After tweaking the format to be 'YYYY-MM-DDTHH:mm:ss.SSSZZ' rather than 'YYYY-MM-dd"T"HH:mm:ss.fffffff"Z"' it worked just fine. When you're trying to debug issues like this, it's always good to keep the format in a separate variable so you can use the same format that you're trying to parse out to display what you're getting. Had you done that, you would have noticed that 'YYYY-MM-dd"T"HH:mm:ss.fffffff"Z"' was messed up due to it printing out 2014-01-Fr"T"11:32:03.fffffff"-08:00". Which obviously isn't quite right.

JSON date, display original date in the server's timezone

For example, I have a string date like this (I'm getting this from the server in json, from rails app)
s = "2013-09-01T00:00:00.000+08:00"
I would like to display it like so
01.09.2013
So I'm using moment.js library for this
moment(s).zone("+08:00").format("DD.MM.YYYY")
>> "01.09.2013"
But I don't know if needed timezone is +08:00. If I skip .zone() call, result would be wrong because my browser is in differnt timezone
moment(s).format("DD.MM.YYYY")
>"31.08.2013"
Even though in my original string I had +08:00 at the end.
So, my question is how can I extract time zone from json date string using pure javascript or moment.js library?
The simplest way I can think of is extracting the last 6 characters manually,
s.slice(s.length - 6, s.length)
> "+08:00"
But maybe there is a better approach for this task?
Just use the parseZone function, like so:
moment.parseZone(s)
Documentation is here.
Alternatively, you can use the older approach, which does the same thing:
moment(s).zone(s)

Using timezones with moment.js fromNow() or from()

I want to show users how long has been elapsed since they performed an action.
The date+time of the action happening is stored on the server, in the server's timezone. That's what's causing the trouble, since if the user's computer's timezone is 12 hours ahead of the server's timezone, then if the user adds something right now, moment.js will show '12 hours ago' as the output of fromNow() rather than just now.
To try to solve this, I'm trying the following method:
var actionTime = moment( action.timeStamp);//time of when user performed action
var serverTime = moment().zone('-07:00'); //current server time
console.debug( serverTime);//outputs Wed Sep 11 2013 15:19:51 GMT-0700
var timeAgo = serverTime.from( actionTime);
But despite of all this, timeAgo still shows the difference between the client's timezone and the server's timezone (i.e showing '12 hours ago' instead of 'now');
Anyone know how to fix this or what I'm doing wrong?
Ideally, you would want to pass a UTC timestamp from your server to the client. That doesn't mean you have to switch your whole server over to UTC, it just means that you would convert from the time in your database to UTC on the server before sending it over the web. Sure, it would be even better if you actually stored times in UTC, but you said you aren't in a position to make that sort of change right now. But let's just work off the assumption that you can't change anything at all on the server.
We'll also assume that your server is fixed to the UTC-07:00 offset. In real life, this would only be true for places like Arizona that don't follow daylight saving time. So if you are in Los Angeles and are in Pacific Time, then some of your data is based on UTC-07:00, but some of it is based on UTC-08:00. That requires a lot more work if you want to do it in JavaScript.
Let's also assume that the input is already a string in ISO8601 format. (If it's not, then let me know and I will adjust this code.)
var s = "2013-09-11 18:00:00"; // from action.timeStamp
var actionTime = moment(s + "-07:00", "YYYY-MM-DD HH:mm:ssZ");
var timeAgo = actionTime.fromNow();
The reason your other code didn't work is because in the first line, you are affected by the time zone of the browser. The zone setter in the second line just changes the zone for formatting, not changing the actual moment in time.
Also, when you dump a moment to the console for debugging, make sure you format it for output. Otherwise you are just looking at its internal property values, which may or may not make sense directly.
I have solved it in a different way, maybe this option was not possible back when the question was asked, but might be easier now.
I used moment-timezone.js (which requires moment.js 2.6.0+).
I set the default timezone to my server's timezone like this:
moment.tz.setDefault("America/New_York"); // "America/New_York" in my case
and then just use it normally. fromNow() will use the timezone in the client to calculate the time that has passed since that moment.
moment(myDatetime).fromNow();
i had the same issue and used the above comments to modify my code. I did the following to get it resolved:
transform(value: string) {
var time = moment(value).utc();
return moment(time, "YYYYMMDD").fromNow();
}
I was missing the .utc() to convert it before I applied the .fromNow()
Things to note this is being used within a Pipe for Ionic 3 and the above code is from the pipe logic.

JSON datetime between bash script and JavaScript

In the same spirit as discussed here, is there a recommended way to generate / parse dates from within a bash script so that it can be interfaced to Javascript Date?
To be precise, I get this strings when doing json encoding of a Javascript Date object:
2011-10-31T10:23:47.278Z
I could put together a bash hack to generate / parse that date format, but I would prefer to avoid reinventing the wheel. Does somebody have a working solution?
I am more interested in the "generating" side: I want to generate current dates from a bash script and save them in a json document (couchdb) so that they can be automatically ordered by the view engine.
The closest I am coming is this:
date -u +"%FT%T.000Z"
Which gives this output:
2011-11-03T06:43:08.000Z
I do not like that I have to put the T, the Z and the milliseconds to 0 manually (I can use %N for nanoseconds, and truncate with sed or whatever, but seems like overkill just to get millisecond precission), and I was hoping that there would be a built-in format token for date which would produce that UTC date. I assumed - wrongly it seems - that the format is common enough that it can be specified with just one format token.
JavaScript can convert many different values into dates. Not sure if that's what you mean, but for example. Your bash could generate this string: "2011/11/10 08:08:08"
When it gets to JavaScript land you can do this
var date = new Date("2011/11/10 08:08:08")
You can also do this:
var now = 1320287813362
var date = new Date(now)
More info on what Date accepts here:
https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Date
Other interesting info here:
What's the best way to store datetimes (timestamps) in CouchDB?

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