How to make DateTime independent from the current culture? - c#

I cam trying to convert a datetime to string and back, but making it so that it works for all cultures.
I basically have a Textbox (tbDateTime) and a label (lbDateTime). The label tells the user, in which format the software expects the input of tbDateTime. The input of the Textbox will be used for an MySQL command.
Currently it works like this:
lbDateTime.Text = "DD.MM.YYYY hh:mm:ss"; // I live in germany
DateTime date = Convert.ToDateTime(tbDateTime.Text);
String filter = date.ToString("yyyy-MM-dd HH:mm:ss");
Now my question:
Is it possible to determine the format-string for lbDateTime.Text based on the current culture?
Which format does the Convert.ToDateTime function uses?
I hope you can help me. I have actually no pc here to test different cultures, so I'm very afraid that I make something wrong.

Instead of using the Convert.ToDateTime method you can use the DateTime.Parse or DateTime.ParseExact methods. Both allow you to pass a culture that tells how you expect the date to be formatted.
The DateTime.ParseExact method also allows you to specify the format you expect, so you can parse more or less any format with this method.
Edit:
Regarding Convert.ToDateTime. The documentation says that the current culture is used when parsing: http://msdn.microsoft.com/en-us/library/xhz1w05e.aspx
The current culture can be found using the System.Threading.Thread.CurrentThread.CurrentCulture property.
Edit2:
Oh. You may also want to use DateTime.TryParse and DateTime.TryParseExact if you are unsure whether the given format is invalid.
Edit3:
Lots of edits here... I see that you want to determine the culture string that matches the date the user has entered. There is no general solution that is guaranteed to work here. Say for instance that the user has entered the date 01.02.11. There is no way to be certain if this date is in day.month.year or month.day.year or year.month.day and so on.
The best you can do is to have a list of expected input cultures and start with the most likely and try to parse the date using that. If that fails, you can try the second most likely and so on...
But this is really not recommended. Either give the user an expected format, or better, use a date input box that ensures that you receive the selected date in an appropriate format.

The Convert.ToDateTime method will call DateTime.Parse to parse the string, using the current culture (CultureInfo.Current).
You can specify a culture when parsing the string. Example:
DateTime data = DateTime.Parse(tbDateTime.Text, new CultureInfo("en-GB"));
You can use DateTime.ParseExact (or DateTime.TryParseExact) to parse the string using a custom date format. Example:
DateTime data = DateTime.ParseExact(tbDateTime.Text, "dd'.'MM'.'yyyy HH':'mm':'ss", CultureInfo.InvariantCulture);

Another solution :
// Specify the current language (used in the current system you are working on)
CultureInfo currentCulture = CultureInfo.GetCultureInfo(CultureInfo.CurrentCulture.ToString());
// Specify the language that we need
CultureInfo myLanguage = CultureInfo.GetCultureInfo("en-US");
// Adapt the DateTime here, we will use the current time for this example
DateTime currentDate = DateTime.Now;
// The date in the format that we need
string myDate = DateTime.Parse(currentDate.ToString(), currentCulture).ToString(myLanguage);

Related

DateTime.TryParse() not working with formatted date dd/MM/yyyy

This code returns (min time 1/1/0001 12:00:00 AM) not Date.Time.Now . Try Parse works for MM/dd/yyyy but not dd/MM/yyyy . Any suggestions
Here is code
DateTime start, end;
DateTime.TryParse(EPSDate12.Text, out start);
string TNow = DateTime.Now.ToString("dd/MM/yyyy HH:mm:ss"); // Works
// string TNow = DateTime.Now.ToString();// works but gives MM/dd/yyyy as expected
DateTime.TryParse(TNow, out end); // No. gives min time (1/1/0001 12:00:00 AM)
Use TryParseExact and supply the format string.
Also examine the return value from TryParseExact to know if it failed or not (it returns a bool)
I see "EPSDate12.Text" which i suspect may be a TextBox: If you're doing this in a UI, make life easy and use a DateTimePicker - you can set the format, the user can type into them just like a textbox, but they don't accept invalid inputs, and all you have to do is get the .Value property which gives you a DateTime
As to why your attempts to parse the string you made don't work, I think it most likely that the date format Parse is using (which is based on the culture settings of the executing thread) is not the same format as the string you prepared using your forced format. Either make sure your forced format is matched to the current culture, or use a culture that matches your forced format, or use [Try]ParseExact to force the format for parsing like you did when creating the string
See https://learn.microsoft.com/en-us/dotnet/api/system.datetime.parse?view=net-5.0#Culture for more info
The datetime value is internally the same. But, ToString() return value, depends on
the local machine culture setup.
Reference article
The default DateTime.ToString() method returns the string
representation of a date and time value using the current culture's
short date and long time pattern. The following example uses the
default DateTime.ToString() method.
For en-US culture(MM/dd/yyyy hh:mm:ss) , it will be in
7/28/2021 11:37:40 AM
If you want to see in en-GB(dd/MM/yyyy hh:mm:ss), you can apply conversion as given below:
var culture = new CultureInfo("en-GB");
MessageBox.Show($"{DateTime.Now.ToString(culture)}");
28/07/2021 11:45:09 AM
you can also specify exact custom format, in which you want to display.
MessageBox.Show($"{DateTime.Now.ToString("dd/MM/yyyy HH:mm:ss tt")}");
28/07/2021 11:45:09 AM
Thanks for suggestions . Yes DateTime.TryParse is not working and it could be format issue
This line of code.
string TNow = DateTime.Now.ToString("dd/MM/yyyy HH:mm:ss");
generates
29/07/2021 14:49:03
which looks OK but fails TryParse

DateTime.TryParse issue, may relate to Globalization Setting in IIS

Basically,I am reading excel file where one of that columns has date format like : dd/MM/yyyy eg: 11/04/2016
When I am using DateTime.TryParse() to parse that string into datetime method TryParse() treated first numbers like month (number 11 in example above). However the same code running on the other computers will take the second number (04 in example above) as the month.
So my question is why there is a difference between them, what actually decide the behavior of TryParse method?
I think the main difference is in IFormatProvider (hard to say if I can't check some settings in target system), but I usually use other method to get proper DateTime object:
DateTime someDate = DateTime.ParseExact(myStringDate, "dd/MM/yyyy", System.Globalization.CultureInfo.InvariantCulture);
It always gives me what I want no matter how client environment is configured.
Hope this helps. :)
From DateTime.TryParse(String, DateTime) documentation:
Because the DateTime.TryParse(String, DateTime) method tries to parse
the string representation of a date and time using the formatting
rules of the current culture, trying to parse a particular string
across different cultures can either fail or return different results.
If a specific date and time format will be parsed across different
locales, use the
DateTime.TryParse(String, IFormatProvider, DateTimeStyles, DateTime)
method or one of the overloads of the TryParseExact method and provide
a format specifier.
That means your computers have different culture settings which is pointed in CurrentCulture property.
Looks like one computer's current culture have dd/MM/yyyy and the other computer's current culture have MM/dd/yyyy as a standard date and time format.
Since you are sure your values are always in dd/MM/yyyy format, I would use DateTime.ParseExact instead of Datetime.TryParse or DateTime.TryParseExact methods like;
var dt = DateTime.ParseExact(yourColumnValue, "dd/MM/yyyy", CultureInfo.InvariantCulture);
Or you can sets all computers current culture to like the first computer but remember, CultureInfo data is not a stable data that might be change in future with a windows update, .NET Framework version or OS version.

Output DateTime date but no time using only CultureInfo

My code:
dateObject.Value.ToString(Model.Culture)
dateObject is of type DateTime? while Model.Culture is of type CultureInfo.
The (culture dependent) output:
17/08/1960 00:00:00
I'd like to remove the 00:00:00 part without having to specify any format provider.
Model.Culture should contains the format for the date already while somewhere else (but where and how?) I'd like to specify not to output any time.
I was thinking to cast DateTime over a Date object but, unfortunately, there is no such object in C#.
Hardcoding the date format directly will result in the impossibility to create a dynamic and culture dependent program.
" without having to specify any format provider"
...
"Hardcoding the date format directly will result in the impossibility to create a dynamic and culture dependent program."
You can use the overload that enables to provide a format string and the culture:
string result = dateObject.Value.ToString("d", Model.Culture);
or you change the culture if that is desired/possible:
System.Threading.Thread.CurrentThread.CurrentCulture = Model.Culture;
string result = dateObject.Value.ToShortDateString();
Maybe you are looking for this:
dateObject.Value.ToString("d", Model.Culture)
Use ToShortDateString it uses the current thread culture.
DateTime dateObject = DateTime.Now;
string s = dateObject.ToShortDateString();
Try the following using string formatting
dateObject.ToString("dd/MM/yyyy");
DATE FORMATS

Returning date in US format

I' like to return this short date in the US format, the current culture of my application is en-GB, but I'd like it in en-US.
Here's the code I have so far:
DateTime.Now.AddYears(-2).ToShortDateString();
You need to ensure that you are using the right culture format string for this to happen.
One way to get this format directly from the culture is:
CultureInfo.GetCultureInfo("en-US").DateTimeFormat.ShortDatePattern
For me this returns M/d/yyyy.
var usShortDatePattern =
CultureInfo.GetCultureInfo("en-US").DateTimeFormat.ShortDatePattern;
DateTime.Now.AddYears(-2).ToString(usShortDatePattern);
The benefit of doing this is that if a user has overridden the Short Date Pattern for en-US in their control panel (Region and Language), they will get the formatting they want.
Taken from the documentation:
DateTime.Now.AddYears(-2).ToString("d", new CultureInfo("en-US"));
Use .ToString() extension method and enter the format:
DateTime.Now.AddYears(-2).ToString("M/d/yyyy");
Custom date format options are documented here:
http://msdn.microsoft.com/en-us/library/8kb3ddd4.aspx
var culture = new CultureInfo("en-us");
string formatedDate = DateTime
.Now
.AddYears(-2)
.ToString(culture.DateTimeFormat.ShortDatePattern, culture);
"I want to apply the en-US short-date-pattern":
DateTime.Now.AddYears(-2).ToString("d", CultureInfo.GetCultureInfo("en-US"));
"I want to apply the pattern M/d/yyyy regardless of whether .NET thinks that's the short-pattern for en-US or not:
DateTime.Now.AddYears(-2).ToString(#"M\/d\/yyyy", CultureInfo.InvariantCulture)
(Same result as above, but if what you are thinking of as "the US format" was actually MM/dd/yyyy, which is also used in the US, then that's the approach you want, but with #"MM\/dd\/yyyy"instead of #"M\/d\/yyyy".
Finally, "I want to find out the en-US short-date-pattern for use with another call:
CultureInfo.GetCultureInfo("en-US").DateTimeFormat.ShortDatePattern

How to convert MM/dd/yyyy to yyyy/MM/dd in C# using globalization

I have a text box in which a user is supposed to enter a date in MM/dd/yyyy format. This date is stored as yyyy/MM/dd in the database.
I want the user to enter the date in MM/dd/yyyy format and later I want to convert it to yyyy/mm/dd so that I can query the database.
How can I convert the user input date MM/dd/yyyy to yyyy/mm/dd?
If you're certain of the input string's format, use DateTime.ParseExact specifying "MM/dd/yyyy", then return the DateTime using .ToString with the appropriate "yyyy/MM/dd" format string.
There's no need to reference anything in the System.Globalization namespace for this.
That said, your database should be storing dates with a datetime format, rather than a string, in which case the format doesn't matter as your DBMS should do the conversion for you.
You can parse the date and format the result:
string str = Date.Parse(myDate).ToString("yyyy/MM/dd");
Alternatively, if the current culture doesn't support that date format and you've already validated the input:
string items[] = myDate.Split('/');
string str = items[2] + "/" + items[0] + "/" + items[1];
When you said globalization, I assume you want the change to be automatic according to current culture
You can setup culture (at Global.asax.cs I suggest)
System.Threading.Thread.CurrentThread.CurrentCulture = System.Threading.Thread.CurrentThread.CurrentUICulture = CultureInfo.GetCultureInfo("the culture you want to set"); //
you do not need to touch any datetime thing, it just happened when you output them.
One thing is not the other.
Not sure why you want to insist on the text entered being MM/dd/yyyy, or why you haven't used a date time picker to make sure it is a date.
But at the point you get the content of the textbox as a date, parse it based on globalisation, or a set of acceptable formats. Now it is a date, and assuming it's a date in the database, format is irrelevant until you come to populate the text box, with some content from the DB, inwhich case you use DateTime's ToString method witha globalisation parameter, usually CultureInfo.CurrentCulture, or if you've got away with it CultureInfo.InvariantCulture.
If it's a string in the DB, then this is the least of your problems.
They key point is if you use dates properly, format is only relevant for Parse, and ToString type methods.
i am using
IFormatProvider culture=new CultureInfo("en-GB",true);
sqlcommand cmd=new sqlcommand("query",con);
cmd.Parameters.AddWithValue("#date",DateTime.Parse(txtdate.Text.Trim(),culture,DateTimeStyles.NoCurrentDateDefault).Date);
for this to work the format property must be set to dd/MM/yyyy
and text box read only property must be false

Categories

Resources