I want to get systems local date/time format and display date from database on this same format. e.g if system date format is like Month dd/yyyy and date stored in database is mm/dd/yyyy format then I need to get local date/time format and convert my stored date into local format.
HTML5 input type="date" this takes default systems date/time format and show date in same format. how can I do this with jquery or javascript.
You could use the JavaScript Date object:
var date = new Date(yearFromDb, monthFromDb, dayFromDb);
date.toLocaleDateString();
EDIT
It seems that the above method is not consistent between different browsers (Chrome, IE, Firefox). Therefore, I think your only option is to get the formatted date string from server side.
Here is a jsFiddle that shows a cross-browser way of getting the users locale, if you can use this to get a formatted date string in the current locale from the backend (if any).
var locale = window.navigator.userLanguage || window.navigator.language;
Related
I want to force clients (web, android, ios) to send the API only time in UTC/GMT.
This means that they get user's local time (using any method), convert it to UTC/GMT, and then send it to the API.
And I want to reject any datetime parameter that is not in UTC/GMT.
In JavaScript, I can get UTC this way:
new Date().toUTCString() which gives this result:
'Mon, 15 Nov 2021 04:26:38 GMT'
And I send this string to the API:
[HttpGet]
public object Parse(string clientDateTime)
{
var date = DateTime.Parse(clientDateTime);
return new
{
ParsedDate = date,
Kind = date.Kind.ToString()
};
}
However, I see that .NET parses this date time as Local and not as Utc. This is in spite of the string containing GMT.
How can I check the incoming datetime and make sure it's UTC/GMT?
You can greatly simplify your problem by using a conventional format for datetime serialization. A common choice for this problem is using the ISO 8601 datetime format.
Here you can find an in depth explanation of this format, but as an example this is a datetime in the ISO 8601 format: 2021-11-15T06:40:48.204Z (the final Z indicates that the datetime represented by this string is UTC)
The main advantage in fixing a format for date and times is that you will know in advance the format and you will be in a much better position to parse the datetime strings on the server.
Using the ISO 8601 format is a good choice, because it is a well known format and it is the standard de facto for the datetime serialization: this basically means that anyone writing a client for your application will be able to comply with the required format. Of course, you are required to clearly document this convention so that your clients (or your fellow developers) will be aware of it.
Another tip is using the DateTimeOffset struct instead of DateTime. DateTimeOffset is basically used to represent a specific point in time and that's exactly what you want: your clients will send you ISO 8601 strings representing a point in time and you want to know that point in time in your application.
Your clients will be able to use any time zone to express the point in time they want to send to your application. Doing this using an UTC datetime or any other time zone is just an implementation detail. Once you have parsed the datetime string to a DateTimeOffset instance, if you really want to, you can check whether it is an UTC time by checking the Offset property: it will be a zero TimeSpan value if the DateTimeOffset instance represents an UTC date and time.
In order to manipulate date in a Javascript client application I strongly suggest to use the Moment.js library. Check this docs to see how to get an ISO 8601 string with Moment.js
You can use this helper method to parse an ISO 8601 string to a DateTimeOffset instance. This implementation allows the client to send you a broad range of ISO 8601 compliant string formats, if you want you can be stricter by reducing the number of allowed formats (see the Iso8601Formats static field in the code).
To summarize:
ask your clients to only send you datetime strings in a format compliant with the ISO8601 specification. Clearly document this choice
for a Javascript client use a library like Moment.js to manipulate date and times. This will be much simpler than using plain old javascript Date objects.
if you are manipulating date time strings representing a specific point in time, use the DateTimeOffset struct instead of the DateTime struct. DateTimeOffset represents a specific point in time expressed in a certain time zone. The Offset property represents the difference between the point in time represented by the DateTimeOffset instance and UTC: its value will be a zero TimeSpan if the DateTimeOffset instance represents an UTC datetime. Notice that the point in time will always be the same regardless the time zone it is referring to, so using UTC doesn't make any real difference (it's just an implementation detail at this point).
use code like this one to parse a DateTimeOffset instance from a string. This code tries as many ISO 8601 compliant formats as possible (this is done in order to accept as many valid formats as possible). If you want, you can decide to be stricter: to do that, just reduce the number of formats in the Iso8601Formats array.
A final note on your code. The behaviour you are observing from DateTime.Parse is exactly the expected one. Check the documentation for DateTime.Parse:
Converts the string representation of a date and time to its DateTime
equivalent by using the conventions of the current thread culture.
DateTime.Parse is basically designed to use the locale settings of the machine running the code.
If you want to learn more on the difference between DateTime and DateTimeOffset you can check this stackoverflow question.
I want to accept dates from the users but I cannot enforce the users to enter the date in a specific format. I have tried going through the momentjs documentation but couldn't really find how its done. I can specify an array of formats but then I'll be tied down to those specific formats only.
I know that MS Excel and many other apps does this. (Take date input in some format and convert it to the application suitable format)
If not with moment.js how else can I achieve this? What could be the algorithm or logic that can achieve this thing.
Thanks!
Moment.js can parse an ambiguous string as a date if you don't specify expected formats. It will first attempt to parse it as an ISO 8601 date format, then as an RFC 2822 format and ultimately fall back to JS Date parsing. Keep in mind the supported formats in a JS Date are inconsistent between browsers.
For this reason it's highly advised to always parse using a set of expected formats and enforce the user to input in one of these. Otherwise you may end up with incorrectly parsed dates.
I have an date input field. The user inputs a date then submits and this date is saved in the database. I have two options on how to do things and I know how to implement both but I'm not too sure what the best practice is as I'm a noob.
Option 1: Take the value read from the date input which is a string and send that to my Spring back-end and then create a date object.
Option 2: Take the value read from the date input and create a Date object in JavaScript and send a date object to my spring controller.
I'm leaning towards option 1 because I'm thinking I will have better error handling in my controller?
Your Question is moot as you will be sending a string of a date back to the server either way.
ISO 8601
Generally best to use the standard ISO 8601 formats when exchanging date-time values as text. For a date that would be YYYY-MM-DD.
java.time
As for performing date-time related work on that date value, I recommend using Java for that. Java offers the industry-leading date-time framework found in the java.time classes, defined by JSR 310. See Oracle Tutorial.
The java.time classes conveniently use the ISO 8601 formats by default when parsing/generating date-time strings.
LocalDate ld = LocalDate.parse( "2019-01-23" ) ; // Parses standard ISO 8601 strings.
String output = ld.toString() ; // Generates "2019-01-23".
I want to format the date based on the current browser locale. Like navigator.language. This works
moment(new Date()).locale(navigator.language).format("llll");
but do I need to use the .locale(navigator.language)? I want to know if I need that explicitly, or does moment use the current locale by default, so that I would just need
moment(new Date()).format("llll");
Thanks
I have a requirement in my project to show a date in the client machine format. I am aware of the property in javascript window.navigator.userLanguage or window.navigator.language.. But it is only returning the language of the client machine like 'en-US', 'en-GB' etc.
If the user customizes the date format of the machine for eg:-dd-MMM-yyyy, is there any way to get that format in Javascript?
Thanks in advance
suhaib
You can use the .toLocaleDateString() method:
var yourDate = new Date();
alert(yourDate.toLocaleDateString());
This doesn't tell your code what the user's selected date format is, but it lets you display a date in whatever the user's format is.
On my PC the above alerts "Tuesday, 26 June 2012".
The .toLocaleTimeString() method does the equivalent thing for the time.
The .toLocaleString() method displays date and time.