Saving DateTime object on UK Dev Server vs US Live Server - asp.net

I have a site that saves a date in my model to the database.
After launching my site I realised that the server has US regional settings so I had to make sure that all date's on the public site were formatted in the UK format.
However now when I go to my 'Create' page and choose a date and click save I get the error The value '22/11/2009' is not valid for the Date field. which must be coming from the default DataAnnotations on my model.
Is there something I can do to get it to accept UK formatted dates?

I managed to get it working by putting this into the web.config
<globalization culture="en-GB"/>

Have you tried this? If this site is only used in the UK, you can probably put this in the Global.asax Application_Init. If it is based on the user, you can put it in Application_BeginRequest. This will provide the default formatting and parsing for all dates and numbers in the application.
Thread.CurrentThread.CurrentCulture = CultureInfo.GetCultureInfo("en-gb");
Thread.CurrentThread.CurrentUICulture = CultureInfo.GetCultureInfo("en-gb");

Do what SO does: persist all dates in UTC and render them as UCT with an appended "Z" for GMT/UTC/Zulu. It might not be ideal but sometimes the gain from simplicity outweighs the costs of the alternative. Think about that.

Related

Datetime.Now method in ASP.NET

I am using ASP.NET to provide some variables for the data that has to be added to a SQL database.
Code I am using:
I am using DateTime.Now to select the current time.
How I use it:
I have two pages, one is a page to insert the posts of the users. Other page is used for ajax purpose, to add some text comments to the posts.
In both page I use the same code.
But the code is executing different values. You can have a look here:
In the post the time is saved as "9/1/2013" which means 1st September, 2013! In comment it is saved as Sep 1 2013, which means the same.
My question: how does the code know that the request is an ajax one or the post one. The post page code is wrapped in if(IsPost) { however the comment is an ajax call.
What is the reason behind this?
I found what the issue was.
I had set the column DataType to nvarchar(50) in the database table. After editing it to DataType DateTime I was able to get the same result. So the issue was not the Culture or DateTime. It was the DataType of the column in SQL Server Database.
Assuming that your AJAX call is not changing the format string of your DateTimes, I would assume the threads which process those 2 different requests are operating under different cultures, which would explain why they're being displayed differently (not sure why though, check your settings perhaps). Try the following and you'll see how culture can effect DateTime output:
Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
Console.WriteLine (DateTime.Now.ToString());
Thread.CurrentThread.CurrentCulture = new CultureInfo("gu-IN");
Console.WriteLine (DateTime.Now.ToString());
Here's some additional information on CultureInfo.
Code knows from Current thread's Culture information. You should use DateTime.Now.ToString("yyyy-MMM-dd") or any other formate according to your needs to be sure of output.

Date conversion on Live Server issue

I have a web application that when working in development is fine, but going to Live it does not work.
What the situation is to do with dates. A user enters in a date in the UK format through a text, and I use DateTime.ParseExact(txtDate.Text, "dd-MM-yyyy", Nothing) to tell the date datatype that the date must remain in UK style. As I say, everything is fine in development, but when it goes to Live, it says the that the string is not a valid datetime format.
I have tried Convert.ToDateTime, and all sorts of things, but it just won't work!
Anyone have any suggestions?
I suspect that the culture setting on the live server is different to that of the dev machine.
From the docs:
If provider is a null reference (Nothing in Visual Basic), the current culture is used.
So you need to specify the InvariantCulture try this:
DateTime.ParseExact(datetimeString, "dd/MM/yyyy",
System.Globalization.CultureInfo.InvariantCulture)

dates behaving differently on different dbs?

I have an asp.net webpage, with a jQuery datepicker on it.
I am in the UK, so when I enter 28/02/2010, I expect it to resolve to 28th Feb 2010.
This is working as expected on my local dev env - but not on our QA or prod-like envs - or one of the other dev machines. In these cases it seems to attempt to resolve it to American date format - and fails validation as it is out of range.
The jQuery seems to generate the correct date each time - which leads me to think it may be a database issue.
I am using SQL Server 2005, my collation is Latin1_General_CI_AS, my colleagues are using collation SQL_Latin1_General_CP1_CI_AS, and a Chinese one.
Given that we don't have control over the prod SQL Server installation (just our db), what is the best way to make this work in a standard way? Change the db settings, or the code that uses it?
Thanks in advance!
- L
[EDIT to add code info]
This is my view code to call the datepicker:
<%=Html.TextBox("DateOfBirth", Model.DateOfBirth.ToShortDateString(), new { #class = "datepicker" })%>
Here is the js for the datepicker:
DatePickerSettings = {
setup: function () {
$(".datepicker").datepicker({
dateFormat: 'dd/mm/yy',
changeMonth: true,
changeYear: true
});
}
};
And this is how I specify the date in the model:
[Required]
[DisplayName("Date of Birth")]
public virtual DateTime DateOfBirth { get; set; }
The date appears correct inthe controller and repository... until it hits the db.
Thanks :)
I was hoping to wait until you'd updated the question with some more information, but as I've seen some answers suggesting that you change the string format you use to talk to the database...
Don't send dates as raw text in SQL queries.
Use a parameterized query, which means you don't need to worry about formatting the value at all. Then you've just got to make sure that you can get the date format correct between the browser and ASP.NET.
Aside from anything else, if you're including user data in SQL queries directly, you'll generally be opening yourself up to SQL injection attacks. Always use parameterized queries (unless your web app is really a "run this SQL" test tool...)
If you're already using parameterized queries, then the problem is likely to be between the browser and ASP.NET, and the database part is irrelevant. Divide and conquer the problem: chase the data as it passes through different layers (browser, jQuery, ASP.NET etc) until you find out where it's gone wrong. Don't even think about a fix until you know where it's gone wrong.
Is your page Culture aware?
You can determine UI Cutlure information for different browsers(locales) and have your ASP.NET Culture constant.
The Culture value determines the results of culture-dependent functions, such as the date, number, and currency formatting, and so on. The UICulture value determines which resources are loaded for the page
Check out this MSDN link:
How to: Set the Culture and UI Culture for ASP.NET Web Page Globalization
http://msdn.microsoft.com/en-us/library/bz9tc508(v=VS.85).aspx
Use CONVERT to change the date format to a standard that is accepted across all environments.
CAST and CONVERT
I'd have to see the code that interprets the dates to know for sure, but a likely suspect is the Region and Language settings on the machines where the code is running. Make sure it is set appropriately for your region.
However, if you can't change settings on the servers, you should probably explicitly use CAST or CONVERT in SQL Server to force it to parse it in the region specific way you expect the data will be entered.
You also need to check your ASP.Net layer, and see what it is running in.
Check the machine configuration and check they are set to run in the same date/time/region.
Change your code to use yyyymmdd format.
As far as i know it works in all the DBs
Just to add another opinion here, I find dd/mmm/yyyy the best date format to send to databases as it's completely unambiguous across cultures.

How to show a UTC time as local time in a webpage?

I have a database that holds a time as UTC. This time can be shown in a webpage, so I’ve been asked to show it as local time in the page as it can be viewed from any country. A colleague mentioned something about getting the country settings from the current thread (on the server) but I couldn’t find any details on this. Is what I want to do possible?
If you (and your website) are comfortable with javascript, there is a very easy way to accomplish this.
First, on the server side, you would have the UTC date/time formatted in RFC 3339 format (the standard for internet time used by, among other protocols, icalendar). The basic syntax of RFC 3339 is:
YYYY-MM-DDTHH:MM:SS
Such that where I am, the time would be:
2010-05-04T05:52:33
But when the time is not local, but UTC, you add a Z to the end to denote this. So in my case, since I'm at -0500 hours from GMT, the same time above would be:
2010-05-04T10:52:33Z
So, first you get the server to output the above to your web page's javascript. The javascript can then parse that timestamp and it will output the date and time adjusted to the browser's time zone (which is determined by the computer hosting the browser). You should remember that if a user is from Tokyo and is viewing your website in Spain, they will see the timestamp in Tokyo time unless they've adjusted their computer's clock.
So the javascript would be:
var time_string_utc = some_server_variable; // timestamp from server
var time_string_utc_epoch = Date.parse(time_string_utc);
var time_utc = new Date();
time_utc.setTime(time_string_utc_epoch);
At this point, you have a javascript date object set to your UTC timestamp. A quick explanation of what happens above:
The first variable assumes you have passed the timestamp string to that variable from the server.
The second variable uses the Date.parse() method to convert the string to an epoch timestamp.
The third variable creates the unset Date object.
The last line line uses setTime method, which sets a Date object from an epoch timestamp.
Now that you have the object, you can output it to the user as you see fit. As a simple experiment, you can use:
document.write(time_utc);
which, if you are in my timezone using the UTC timestamp I started off with:
2010-05-04T10:52:33Z
would give:
Tue May 04 2010 05:52:33 GMT-0500 (CST)
but you can use various javascript methods to format the time into something much more pleasant looking.
No need to guess the user's country or even adjust your timestamp, so long as you trust the user's local browser/computer time zone.
Again, the short version:
var time_string_utc = some_server_variable; // UTC time from server
var time_string_utc_epoch = Date.parse(some_server_variable);
var time_utc = new Date();
time_utc.setTime(time_string_utc_epoch);
document.write(time_utc);
Also consider reading this thread which dives deeper in the dos and donts of handling daylight saving problem across timezones
Of-course is possible. You just need to find that country settings to detect the country your user comes from, and then modify the displayed date to fit that country's time.You can also find another way to detect the user country.(maybe from his ip address).
I am sure that the best way to manage this is let your colleague know that you need more details about the country settings implementation on your project and how can you use it.
EDIT:
Thinking about it I don't think it is possible to display the local time once you have the client’s culture. I'd certainly be interested to see your colleagues suggestion.
Getting the US culture, for example, won't help as the US has many timezones.
I think using Javascript like Anthony suggests would be the way to go...
OLD:
You can override the InitializeCulture() method with code that sets the current (chosen or browser reporting) cultures:
Thread.CurrentThread.CurrentCulture =
CultureInfo.CreateSpecificCulture(selectedLanguage);
Thread.CurrentThread.CurrentUICulture = new
CultureInfo(selectedLanguage);
this is how I've done it in PHP in the login file which connects to MySQL database:
//set local timezone
date_default_timezone_set('America/Denver'); //use local TZ
Then, every time you access the DB, you are setting the timezone for that session and any input/output associated with it.

Displaying proper date format depending on culture

I am using a control for a popup calendar date picker. This uses a javascript function, SetText, to set the textbox to the given date. I can't change anything in the calendar control itself but I can override the SetText function. The SetText javascript just takes the TextBox name and the date value in string format and sets the TextBox to the string.
The problem:
I need to display the date in the format "April 30".
Easy to do. Use getMonth() and getDate() where I can parse the information from there.
Now, I need to make sure this shows correctly for different cultures. For example, the UK shows dates as "30 April". Since the code-behind(c#) could be sending the date in the UK format how do I know in the javascript that they're using UK(dd/mm/yyyy) and not US(mm/dd/yyyy)?
The browsers navigator language could be set to one setting while the server is set to another to cause a January 4 as April 1 mismatch.
You are using the Microsoft Ajax Framework, this framework defines a set of "client-side type extensions" which provide added functions or "extensions" to the JavaScript base types.
The Date Type Extensions is what you're looking for, specifically the Date.parseLocale function.
With this function you can parse a string, using a given format.
You can synchronize your server-side and client-side culture by setting the ScriptManager.EnableScriptGlobalization property to true, and use the Date.parseLocale function without specifying any format.
Give a look to this article:
Walkthrough: Globalizing a Date by Using Client Script
See toLocaleString and related functions.
If you control the backend, why not just send a timestamp and push it into Date object?
As for formatting on the client side, since I was already using Dojo, I solved this problem by using dojo.date.locale.format. It was completely painless.
Locale is detected automatically or can be set arbitrarily.
Shorthand format options (e.g.: long short)
Data selectors (e.g.: time, date)
Ability to specify an arbitrary date/time pattern (probably not application to this application, but still useful).
Tutorial: http://docs.dojocampus.org/dojo/date/locale
API doc:
http://api.dojotoolkit.org/jsdoc/1.3/dojo.date.locale.format
Date format descriptions: http://www.unicode.org/reports/tr35/tr35-4.html#Date_Format_Patterns
Three things you could use:
1) toLocaleString - As suggested already. The problem with this is when sending a string of "4/1/2009" this can result in a couple things. January 4 or April 1.
2) navigator.language and navigator.systemLanguage - After you get the date string you can check to see what language the system is in and parse the date from there. The problem with this and solution 1 is what if you have a UK server and the browsers machine is US. You will have the code behind sending April 1 as 1/4/2009 where the javascript will read the string as whatever language the clients browsers is. So, UK server and US browser will give you a wrong result.
3) Use Code Behinds Culture - Create a variable in your javascript that when the page loads, it will call a function in your code behind that returns this.Page.Culture from there, you will know what culture the string is being sent back as. This will eliminate the mismatch that the first two solutions can cause. It will take a little extra work to make sure it's displayed correctly but at least you will be able to use the string without having the possibility of mismatching cultures.
toLocaleDateString would be a better solution than toLocaleString for your problem as it doesn't include the time (as you only are requesting the date).
The open-source JavaScript library Date.js has some great methods for formatting dates, as well as it supports a bunch of languages:
Date.js at Google Code: http://code.google.com/p/datejs/
If you want nicely formatted dates / times, you can just pass a formatting string (nearly identical to those used in .NET Framework) into any Date object's .toString() method.
It also has a whole set of cultures which allow you to simply include the appropriate script for that culture.
If you want to manage that yourself (as we do in our apps), you can find resources which give you the list of appropriate resource strings for a given culture. Here's one that shows proper formatting strings for a ton of cultures: http://www.transactor.com/misc/ranges.html
As you are using ASP.NET then you may also be using ASP.NET Ajax. If so, there are two properties on the ScriptManager that are of use to you:
EnableScriptLocalization - Gets or sets a value that indicates whether the ScriptManager control renders localized versions of script files.
EnableScriptGlobalization - Gets or sets a value that indicates whether the ScriptManager control renders script that supports parsing and formatting of culture-specific information.
<asp:ScriptManager ID="AjaxManager" runat="Server" EnablePartialRendering="true"
EnableScriptGlobalization="true" EnableScriptLocalization="true" />
When you enable both of these (set to true) then ASP.NET Ajax extenders etc. should automatically be localised into the culture specified in web.config:
<configuration>
<system.web>
<globalization
fileEncoding="utf-8"
requestEncoding="utf-8"
responseEncoding="utf-8"
culture="en-GB"
uiCulture="en-GB" />
</system.web>
</configuration>
For instance, setting this will localise the AjaxControlToolkit Calendar into your specificed culture.
Even if you are NOT using ASP.NET Ajax adding a ScriptManager and enabling localisation will give you a useful javascript variable called __cultureInfo that contains a JSON array of localised formate, such as currencies, dates etc.
"CalendarType":1,"Eras":[1],"TwoDigitYearMax":2029,"IsReadOnly":true},"DateSeparator":"/","FirstDayOfWeek":1,"CalendarWeekRule":0,"FullDateTimePattern":"dd MMMM yyyy HH:mm:ss","LongDatePattern":"dd MMMM yyyy","LongTimePattern":"HH:mm:ss","MonthDayPattern":"dd MMMM","PMDesignator":"PM","RFC1123Pattern":"ddd, dd MMM yyyy HH\u0027:\u0027mm\u0027:\u0027ss etc....
I solved this problem by using Datejs as
In codebehind(aspx.cs) I get the culture for an employee and add the appropriate js to the header as
string path =
"http://datejs.googlecode.com/svn/trunk/build/date-"
+ GetCulture() + ".js"; Helper.AddJavaScript(this, path);
(in your case you can get the culture from navigator.systemLanguage (or navigator.browserLanguge etc) and add a script tag to the header with src attribute pointing to the appropriate path)
On the client-side I use
d.toString(Date.CultureInfo.formatPatterns.shortDate)
where d is any date object
(I tried using Date.today().toShortDateString() but it was throwing exception. (the CultureInfo JSON object had a different structure than what the function expects).

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