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Change System Date Format At Runtime

, 16 Mar 2011 CPOL
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Change System Date Format At Runtime


You may sometimes need to change your system Date format at run time. C# has namespace ‘using Microsoft.Win32’ which helps you to change your system date and currency format.

Using the Code

First, you just have to use namespace using Microsoft.Win32

Then use RegistryKey class to access Current user preferences. Then you can set value for date format using RegistryKey’s object.

//    RegistryKey rkey = Registry.CurrentUser.OpenSubKey
//                (@"Control Panel\International", true);
//      rkey.SetValue("sShortDate", "d/M/yy");
//    rkey.SetValue("sLongDate","dd/MM/yy");
  • d:

    Use this to specify the numeric value for the day of the month.

    Eg. d (1) or dd(01) or ddd(MON) or dddd(MONDAY).

  • M:

    These display the months in numeric form.

    Eg. M(1) or MM(01) or MMM(JAN) or MMMM(JANUARY).

  • y:

    Use this to specify the numeric value for the year to different digits.

    Eg. y(9) or yy(09) or yyyy(2009).

Apart from these, you may also use follow:
  • t: The first character of the AM/PM designator.

    11/03/2011 1:45:30 PM

  • tt: The AM/PM designator.

    11/03/2011 1:45:30 PM

  • s: The second, from 0 through 59.

    11/03/2011 1:45:09 PM

  • ss: The second, from 00 through 59.

    11/03/2011 1:45:09 PM. and so on

Points of Interest

This is very easy code to change system date format at runtime. Following are the class methods with their uses.
// RegistryKey, represents a key-level node at windows registry
// Registry, represents a root keys in windows registry
// CurrentUser, reads windows registry base key HKEY_CURRENT_USER
You can use this code to change system currency format too.


15 March 2011: Initial release


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


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Comments and Discussions

QuestionHow to set time? PinmemberMember 938534217-Sep-13 0:00 
GeneralReason for my vote of 5 very nice tips... Its work PinmemberSona s25-Mar-11 4:22 
GeneralYou r going good best wishes... PinmemberBhavna v24-Mar-11 19:12 
GeneralReason for my vote of 5 Nice tips, I just have been lookung ... PinmemberBhavna v16-Mar-11 17:02 
GeneralDon't do that! PinmemberBernhard Hiller16-Mar-11 23:03 
A program which changes my system settings would quickly be removed from my computer.
If the program wants to use some specific different date/time format, it may use the parameters of the ToString() or Parse() method of the DateTime class - and I'd find it still inconvenient to see dates in a different format than expected.
I did not rate your tip: for providing others with the idea of changing system settings, you deserve 1, but technically the tip looks correct.

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