I have a use-case in which I need a user to enter an availability date on the browser (which will be saved in the database in UTC format) for example
July 2nd at 6:30PM,
i am getting IANA location string using momentjs
moment.tz.guess(); //'America/New_York'
now when I do the server side rendering, I would like to render the availability date as
July 2nd at 6:30 EST
or
July 2nd at 6:30 PMT
Is there a javascript library to do this for me? how can I convert 'America/New_York' to EST?
worth mentioning it is a reactjs application
we can achieve this by momentjs. get the IANA timezone with guess() function as explained above to set the timezone and then format it with as documented in moment documents
const date = user input date saved in the database
const z = value of moment.tz.guess() which saved in db
moment(date).tz(z).format('MM/DD/YYYY hh:mm A z');
Related
The ability to use date formatting in the Slack API to display a date/time in the local timezone of the person seeing the message is great, but I'd like people to know that the date/time is in their local timezone.
Using <!date^1392734382^{date_short_pretty} {time}|2014-02-18 6:39 AM PST> will display as "Posted Feb 18, 2014 6:39 AM" if the receiver is in California, and "Posted Feb 18, 2014 8:39 AM" if the receiver is in Chicago (see here in Block Kit Builder) but there is no indication to the receivers that the date/time is in their own timezone.
Is there any way to include the receiver's time zone as part of the token string?
This is not a feature that is provided by the API. The only solution I can think of is to add some info text like "(local time)" to the datetime output in your message.
I am getting some results from a weather API and one of that is date in epoch time stamp.
I found that converting with Date(timeIntervalSince1970:) I get the right date
I am using the specific number --> 1501452000 and I get 2 results on Playground
1) Jul 31,2017,12:00AM. -- when --> let date = Date(timeIntervalSince1970: 1501452000)
2) 2017-07-30 22:00:00 +0000 when --> print(date)
API results are :
"time_epoch": 1501452000,
"time": "2017-07-30 23:00",
By checking the rest of my results they are matching with the rest of the API results....... but when I convert 1501452000 -> to date I don't get the correct Hour 23:00 but 22:00 !
Any idea what is happening ?
is it wrong the API( I don't think so ) or the way I am converting it?
Thanks a lot
The timeIntervalSince1970 initializer sets up the time in the UTC timezone, while your API might be sending dates in GMT. When you are using print(data), you have different results, because if you are not using a DateFormatter to generate the String format of the Date object, it uses your devices current settings when formatting the Date object.
A Date object represents an absolute point in time, but when you are printing it with a DateFormatter, it gets converted into a location/time zone specific, relative representation. You just have to set up your DateFormatter to match the time zone settings of your API and you will see the dates correctly printed.
This issue happens on daylight saving times. Is your country changing daylight saving on this exact date?
let date = Date(timeIntervalSince1970: 1501452000) in Playgrounds should give you the time in your system's timezone when you see it on the right hand side.
When you print it and see 2017-07-30 22:00:00 +0000- this is the same timestamp in GMT
Is the API showing a particular time zone? It looks like GMT+1
I am trying to save a time string in the database in the form of HH:MM AM/PM format. e.g. 12:00 AM to 11:00 PM. These strings are already defined in the code. What is the best data type to store these strings in database using SQL Server 2012.
What is the better way? a generic list in the code to populate values when page loads and then store or store all values in the database from 12:00 AM to 11:00 PM and then get from database.
If you use DateTime or DateTime2 in the database it's a 24 hour clock, there is no AM/PM format. You get an AM/PM format by doing this in the code:
dateTime.ToString("tt", CultureInfo.InvariantCulture);
Background: I'm building an app with Angular JS as web interface and Rails API. The problem I am having is passing a date from Angular to Rails.
Issue: I have a form with a Date of Birth date field, when a user inputs his DOB say March 1st, 1985, Angular interprets it as 1985-03-01 00:00 +0800 (if you're in Hong Kong or Singapore) and sends a request to Rails. The first thing Rails does with it is to convert it to UTC, which means the datetime is now 1985-02-28 16:00 UTC. Therefore, when the date is saved to the database date column, it becomes Feb 28, 1985.
Solution for now: What I'm doing now is on Angular side, I get the Timezone offset hours and add it to the date, so instead of 1985-03-01 00:00 +0800, it is now 1985-03-01 08:00 +0800. When Rails get it, it converts to 1985-03-01 00:00 UTC and so saves the correct date to db. However, I believe this is a better alternative to tackle this issue.
Thinking about parsing just the date in Rails, yet the params[:dob] I see is already UTC by the time I get it. Would love to know if there is a better practice than my current solution. Thank you for any comment and feedback.
This problem is actually quite common, and stems from two separate but related issues:
The JavaScript Date object is misnamed. It's really a date + time object.
The JavaScript Date object always takes on the characteristics of the time zone for the environment in which it is running in.
For a date-only value like date-of-birth, the best solution to this problem is to not send a full timestamp to your server. Send just the date portion instead.
First, add 12 hours to the time, to use noon instead of midnight. This is to avoid issues with daylight saving time in time zones like Brazil, where the transition occurs right at midnight. (Otherwise, you may run into edge cases where the DOB comes out a day early.)
Then output the date portion of the value, as a string in ISO format (YYYY-MM-DD).
Example:
var dt = // whatever Date object you get from the control
dt.setHours(dt.getHours() + 12); // adjust to noon
var pad = function(n) { return (n < 10 ? '0' : '') + n; }
var dob = dt.getFullYear() + '-' + pad(dt.getMonth()+1) + '-' + pad(dt.getDate());
Another common way to do this is:
var dt = // whatever Date object you get from the control
dt.setHours(dt.getHours() + 12); // adjust to noon
dt.setMinutes(dt.getMinutes() - dt.getTimezoneOffset()); // adjust for the time zone
var dob = dt.toISOString().substring(0,10); // just get the date portion
On the Rails side of things, use a Date object instead of a DateTime. Unlike JavaScript, the Rails Date object is a date-only object - which is perfect for a date-of-birth.
In my client application I have the Latitude & longitude information from skyhook API based on its I.P.
Now based on the latitude and longitude information I need to find out the timezone information of the client. But in the google timezone API documentation https://developers.google.com/maps/documentation/timezone/ I see that timestamp is a mandatory field. In which case what should I need to do.
Also can you kindly help me understand what does the timestamp corresponds to? For e.g :- If my Application server is in U.S.A (say PST timezone) and it makes the google API call passing the server timestamp.
If user logs into client application from India passing lat / long information, to the app server to get the timezone information what will the API provide as dstOffset and rawOffset? i.e If I add the server timestamp with dstOffset and rawOffset will I be getting the client machine timezone information?
I've been scratching my head on Google's Timezone API for a few minutes, specifically on the timestamp parameter. Maybe this will lay out the need:
In San Diego, we (now, in August) have a GMT offset of -8 because of daylight savings time. However, in November we'll have a GMT offset of -7.
So which gmt offset should Google return? -7 or -8? They're both valid, but it depends on what day you take the measurement.
Enter the Timestamp argument. Running the service now, and using a timestamp value of August 2015, I get this response:
{
"dstOffset" : 3600,
"rawOffset" : -28800,
"status" : "OK",
"timeZoneId" : "America/Los_Angeles",
"timeZoneName" : "Pacific Daylight Time"
}
But if I bump the timestamp to November 2015 (once San Diego is out of daylight savings, I end up with this):
{
"dstOffset" : 0,
"rawOffset" : -28800,
"status" : "OK",
"timeZoneId" : "America/Los_Angeles",
"timeZoneName" : "Pacific Standard Time"
}
In both cases the rawOffset is the same, but the DST changed because of the timestamp I provided. If you just want to know the raw timezone, the timestamp doesn't matter.
But if you want an application to reliably do something at 8:00am in San Diego in August and 8:00am in November in San Diego, you'll need to engage the timestamp.
Putting it another way, what's the value of knowing that San Diego is normally -7 hours offset from GMT. If you're working with timezones, you're likely trying to ensure that your UTC time is matched up with what a real person in that location is experiencing. As such, the DST offset is critical.
The documentation link you provided clearly states that the timestamp should be in UTC and that it is used to show the correct DST offset value. It will also control if the timeZoneName field is shown with "Standard" or "Daylight" in the name.
If you don't care about that and just want the timeZoneId field, then it doesn't matter what value you pass.
Try this
DateDiff("s", "1/1/1970", DateTime.Now)