Create custom DateTime format respective of locality in .NET C# - c#

So this seems like an easy thing to do, but still has me stumped. I want to display a list of strings to my user, based off of a few file's creation dates. So basically, display a list of DateTimes. The challenge is that want to use a custom format (something like 5/6/13 12:01 PM) but I want he date part of that to display differently based on how you have your system displaying the date (ie. a Brit would display that date as 6/5/13).
I thought I could just build two strings (one for date and one for time) and make sure that they date is region-formatted, but there is no default option for 5/6/13 (only 5/6/2013):
http://msdn.microsoft.com/en-us/library/az4se3k1.aspx
Next I hoped maybe the DateTime.ToShortDateString() function would work, but it displays as 5/6/2013 as well.
I know I can use a completely custom format like this: DateTime.ToString("M/d/yy h:mm tt") but I don't want to fix the date with the month before the day.
I suppose if I can' figure anything out then I could just build a custom datetime for America and for Europe and then query the OS for what datetime they are displaying in. But that seems really excessive. Any thoughts?

You could retrieve the current ShortDate format from current culture, change it and use it with ToString()
var currentDate = DateTime.Now;
var shortDateFormat = CultureInfo.CurrentCulture.DateTimeFormat.ShortDatePattern;
var newShortDateFormat = shortDateFormat.Replace("yyyy", "yy");
Console.WriteLine(currentDate.ToString(shortDateFormat));
Console.WriteLine(currentDate.ToString(newShortDateFormat));

System.Globalization.CultureInfo implements IFormatProvider, so you can provide a CultureInfo object as a parameter to the ToString method.
MSDN seems to have an example of exactly what you want.

Related

Querying with Arabic (Hijri) DateTime

I essentially have a query that looks like this:
.Where(x=>x.Date < DateTimeOffset.UtcNow)
Now, this has worked as intended so far, but since also adding Arabic into my application, apparently their calendar system uses something called a Hijri calendar?
Anyway, date such as 24/09/2013 looks like 18/05/34 (invented values).
So, the query would end up using the 18/05/1834 date, and thus return no values.
tl;dr I want to be able to query with the non-cultured datetime.
I've tried to google how to use CultureInvariant, but all the solutions showed a .ToString() whereas I need a datetime returned
DateTime and DateTimeOffset don't have any culture. You only use culture info when parsing a string or outputting a string. Internally, they always store their data using the Gregorian calendar. So if you are comparing DateTime or DateTimeOffset values, then it doesn't matter what calendar system is used for display - the comparison will always be done with their Gregorian equivalents.
You had said in your question:
So, the query would end up using the 18/05/1834 date, and thus return no values.
If you are doing things normally, that won't be true. You won't have Hijri formatted dates in your database. Those will all be Gregorian still and the comparison should work as expected. If for some reason you actually have the Hijri values in your data, then somewhere you are passing your values by string, which is getting affected by culture. You shouldn't do that.
Take a look at the sample code in this MSDN entry. It shows clearly that you need to use a calendar object to get numerical equivalents for each part, but there is no way to get back a single non-string value that represents the entire date in a non-Gregorian calendar system.
For example:
DateTime utc = DateTime.UtcNow;
Calendar cal = new HijriCalendar();
int y = cal.GetYear(utc);
int m = cal.GetMonth(utc);
int d = cal.GetDayOfMonth(utc);
Or, as a string:
DateTime utc = DateTime.UtcNow;
var ci = CultureInfo.CreateSpecificCulture("ar-SA");
string s = utc.ToString(ci);
If you want a better way to represent Hijri calendar dates in your code, you might consider using Noda Time instead of the built-in types. It has much better support for alternative calendars. For example:
Instant now = SystemClock.Instance.Now;
CalendarSystem cal = CalendarSystem.GetIslamicCalendar(IslamicLeapYearPattern.Base15, IslamicEpoch.Civil);
ZonedDateTime zdt = now.InZone(DateTimeZone.Utc, cal);
LocalDateTime ldt = zdt.LocalDateTime;
UPDATE
It appears the question was with specific regard to querying in RavenDB, and was discussed here. The problem was tracked down to a culture related bug in RavenDB, and fixed in release 2.5.2715.

datetime format : can a computer be forced to use a particular format?

I have developed a winform application that makes use of the format dd-MM-yyyy hh:mm:ss (24 hr system).
When I try the application on another computer, I get an error, because the standard datetime format there is dd/MM/yyyy hh:mm:ss am/pm.
Moreover, the controls in which the datetime is stored, also hold the datetime string in a different format: d/M/yyyy hh:mm:ss am/pm, eg 1/4/2013 12:00:00 A.M. instead of 01/04/2013 12:00:00 A.M.
Can I force the other system to somehow use the same format?
I am a novice here. Thanks for the help.
When displaying a DateTime object, there are two things to keep in mind.
Culture settings: when you don't specify an explicit culture, the culture that's set by the system your application is running on is used.
Format strings: when converting a DateTime object to a string, you can give it a format string as an argument that specifies how your DateTime object should be formatted. Something like: "d" for a short date pattern or "t" to only display the time.
Combining these two will give you full control over how to display your DateTime objects. You should however be careful in forcing a certain culture setting on the user. If your application should support globalization (so multiple users from different cultures can use your app) you shouldn't depend on a specific culture. Instead, you should store all your data culture-insensitive and format it with the users culture when you display it on screen.
Here is an example how to use both the CultureInfo object and a format string:
string myDate = "10-05-2013 08:52:30";
DateTime date = DateTime.Parse(myDate);
Console.WriteLine(date.ToString("d", new CultureInfo("en-US"))); // 5/10/2013
Console.WriteLine(date.ToString("d", new CultureInfo("nl-NL"))); // 10-5-2013
Console.WriteLine(date.ToString("f", new CultureInfo("nl-NL"))); // vrijdag 10 mei 2013 08:52
You should be able to set the culture for the application to the one you need to use.
System.Threading.Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo("EN");
I would not recommend to force the system to one date and time format. From my point of view the better question would be, why is your application using a specified format? The .NET Framework is designed that you don't have to care about such things.
Anyway, if you will really force the system to display the data in a specified format, change the thread culture:
System.Threading.Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo("de-DE")
System.Threading.Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("de-DE")

How to make DateTime independent from the current culture?

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);

.NET DateTime to BizTalk DateTime

I have date in this format "1999-05-31T13:20:00.000-05:00" I want to add some hours or days to it . BizTalk expects same datetime format how can i pass it as Datetime in that format ? No string . Date time with same format as source date.
You should be able to do something like this to get it into a DateTimeOffset object. After that you can call whatever methods you want on it.
DateTimeOffset dateTime = DateTimeOffset.Parse( "1999-05-31T13:20:00.000-05:00" );
To get the value back just use a formatting string.
dateTime.ToString( "O" ); //this should be the same format as you started with
Here are some other options http://msdn.microsoft.com/en-us/library/az4se3k1.aspx
Here is a link to the DateTimeOffset structure
http://msdn.microsoft.com/en-us/library/bb351654.aspx
I hope this helps.
The DateTime object is format-independent (for the most part). So whether or not it starts in the format you list or not doesn't matter. You can always get it back into that format (using the ToString("o") function). But that's as a string (when format matters).
After a quick search, it looks like you must be talking about string format, even though you said no string. So the other answer or the ToString("o"); part of mine is relevant.

DateTimePicker: pick both date and time

Is it possible to use DateTimePicker (Winforms) to pick both date and time (in the dropdown)? How do you change the custom display of the picked value? Also, is it possible to enable the user to type the date/time manually?
Set the Format to Custom and then specify the format:
dateTimePicker1.Format = DateTimePickerFormat.Custom;
dateTimePicker1.CustomFormat = "MM/dd/yyyy hh:mm:ss";
or however you want to lay it out. You could then type in directly the date/time. If you use MMM, you'll need to use the numeric value for the month for entry, unless you write some code yourself for that (e.g., 5 results in May)
Don't know about the picker for date and time together. Sounds like a custom control to me.
It is best to use two DateTimePickers for the Job
One will be the default for the date section and the second DateTimePicker is for the time portion. Format the second DateTimePicker as follows.
timePortionDateTimePicker.Format = DateTimePickerFormat.Time;
timePortionDateTimePicker.ShowUpDown = true;
The Two should look like this after you capture them
To get the DateTime from both these controls use the following code
DateTime myDate = datePortionDateTimePicker.Value.Date +
timePortionDateTimePicker.Value.TimeOfDay;
To assign the DateTime to both these controls use the following code
datePortionDateTimePicker.Value = myDate.Date;
timePortionDateTimePicker.Value = myDate.TimeOfDay;
Unfortunately, this is one of the many misnomers in the framework, or at best a violation of SRP.
To use the DateTimePicker for times, set the Format property to either Time
or Custom (Use Custom if you want to control the format of the time using
the CustomFormat property). Then set the ShowUpDown property to true.
Although a user may set the date and time together manually, they cannot use the GUI to set both.
DateTime Picker can be used to pick both date and time that is why it is called 'Date and Time Picker'. You can set the "Format" property to "Custom" and set combination of different format specifiers to represent/pick date/time in different formats in the "Custom Format" property. However if you want to change Date, then the pop-up calendar can be used whereas in case of Time selection (in the same control you are bound to use up/down keys to change values.
For example a custom format " ddddd, MMMM dd, yyyy hh:mm:ss tt " will give you a result like this : "Thursday, August 20, 2009 02:55:23 PM".
You can play around with different combinations for format specifiers to suit your need e.g MMMM will give "August" whereas MM will give "Aug"
Go to the Properties of your dateTimePickerin Visual Studio and set Format to Custom. Under CustomFormat enter your format. In my case I used MMMMdd, yyyy | hh:mm
You can get it to display time. From that you will probably have to have two controls (one date, one time) the accomplish what you want.
I'm afraid the DateTimePicker control doesn't have the ability to do those things. It's a pretty basic (and frustrating!) control. Your best option may be to find a third-party control that does what you want.
For the option of typing the date and time manually, you could build a custom component with a TextBox/DateTimePicker combination to accomplish this, and it might work reasonably well, if third-party controls are not an option.
If you need (24 hours) military time. You should use "HH" instead of "hh".
"MM/dd/yyyy HH:mm"

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