Csharp/C Sharp/Development Class/Date Time Format

Compare the results of choosing InvariantInfo with those of choosing CurrentInfo:

 

using System;
using System.Globalization;
public class MainClass {
    public static void Main() {
        DateTime dt = new DateTime();
        DateTimeFormatInfo dtfi;
        Console.Write("[I]nvariant or [C]urrent Info?: ");
        if (Console.Read() == "I")
            dtfi = DateTimeFormatInfo.InvariantInfo;
        else
            dtfi = DateTimeFormatInfo.CurrentInfo;
        dtfi = DateTimeFormatInfo.InvariantInfo;
        Console.WriteLine(dt.ToString("D", dtfi));
        Console.WriteLine(dt.ToString("f", dtfi));
        Console.WriteLine(dt.ToString("F", dtfi));
        Console.WriteLine(dt.ToString("g", dtfi));
        Console.WriteLine(dt.ToString("G", dtfi));
        Console.WriteLine(dt.ToString("m", dtfi));
        Console.WriteLine(dt.ToString("r", dtfi));
        Console.WriteLine(dt.ToString("s", dtfi));
        Console.WriteLine(dt.ToString("t", dtfi));
        Console.WriteLine(dt.ToString("T", dtfi));
        Console.WriteLine(dt.ToString("u", dtfi));
        Console.WriteLine(dt.ToString("U", dtfi));
        Console.WriteLine(dt.ToString("d", dtfi));
        Console.WriteLine(dt.ToString("y", dtfi));
        Console.WriteLine(dt.ToString("dd-MMM-yy", dtfi));
    }
}

DateTime ToString with CultureInfo

 
using System;
using System.Globalization;
using System.Threading;
class Program {
    static void Main(string[] args) {
        DateTime d = new DateTime(2005, 08, 09);
        Console.WriteLine(d.ToLongDateString());
        Console.WriteLine(d.ToString("D", new CultureInfo("fr-FR")));
        CultureInfo ci = Thread.CurrentThread.CurrentCulture;
        Console.WriteLine(ci.ToString() + ": " + d.ToString("D"));
        ci = new CultureInfo("es-ES");
        Thread.CurrentThread.CurrentCulture = ci;
        Console.WriteLine(ci.ToString() + ": " + d.ToString("D"));
    }
}

demonstrates culture formatting

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy
Publisher: Sybex;
ISBN: 0782129110
*/
/*
  Example21_10.cs demonstrates culture formatting
*/
using System;
using System.Globalization;
public class Example21_10 
{
  public static void Main() 
  {
    // create a date and a currency value
    DateTime dtNow = DateTime.Now;
    Double curOriginal = 12345.67;
    // and format the variables for a specific culture
    CultureInfo ci = new CultureInfo("en-US");
    string sLocalizedDate = dtNow.ToString("d", ci);
    string sLocalizedCur = curOriginal.ToString("c", ci);
    // print them out
    Console.WriteLine(sLocalizedDate);
    Console.WriteLine(sLocalizedCur);
    // and format them for a second culture
    CultureInfo ci2 = new CultureInfo("en-GB");
    string sLocalizedDate2 = dtNow.ToString("d", ci2);
    string sLocalizedCur2 = curOriginal.ToString("c", ci2);
    // print them out again
    Console.WriteLine(sLocalizedDate2);
    Console.WriteLine(sLocalizedCur2);
  }
}

Format time and date information 1

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Format time and date information. 
  
using System;  
  
public class CustomTimeAndDateFormatsDemo {  
  public static void Main() {  
    DateTime dt = DateTime.Now; 
 
    Console.WriteLine("Time is {0:hh:mm tt}", dt); 
    Console.WriteLine("24 hour time is {0:hh:mm}", dt); 
    Console.WriteLine("Date is {0:ddd MMM dd, yyyy}", dt); 
 
    Console.WriteLine("Era: {0:gg}", dt); 
 
    Console.WriteLine("Time with seconds: " + 
                      "{0:HH:mm:ss tt}", dt); 
 
    Console.WriteLine("Use m for day of month: {0:m}", dt); 
    Console.WriteLine("use m for minutes: {0:%m}", dt); 
  } 
}

Format time and date information 2

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Format time and date information. 
  
using System;  
  
public class TimeAndDateFormatDemo {  
  public static void Main() {  
    DateTime dt = DateTime.Now; // obtain current time 
 
    Console.WriteLine("d format: {0:d}", dt); 
    Console.WriteLine("D format: {0:D}", dt); 
 
    Console.WriteLine("t format: {0:t}", dt); 
    Console.WriteLine("T format: {0:T}", dt); 
 
    Console.WriteLine("f format: {0:f}", dt); 
    Console.WriteLine("F format: {0:F}", dt); 
 
    Console.WriteLine("g format: {0:g}", dt); 
    Console.WriteLine("G format: {0:G}", dt); 
 
    Console.WriteLine("m format: {0:m}", dt); 
    Console.WriteLine("M format: {0:M}", dt); 
 
    Console.WriteLine("r format: {0:r}", dt); 
    Console.WriteLine("R format: {0:R}", dt); 
 
    Console.WriteLine("s format: {0:s}", dt); 
 
    Console.WriteLine("u format: {0:u}", dt); 
    Console.WriteLine("U format: {0:U}", dt); 
 
    Console.WriteLine("y format: {0:y}", dt); 
    Console.WriteLine("Y format: {0:Y}", dt); 
  } 
}

Request a specific culture (english language in Great Britain):

 
using System;
using System.Globalization;
public class MainClass {
    public static void Main() {
        CultureInfo uk = CultureInfo.GetCultureInfo("en-GB");
        Console.WriteLine(3.ToString("C", uk));      // ?¡ê3.00
    }
}

The next example formats a DateTime with invariant culture. Invariant culture is always the same, regardless of the computer"s settings:

 
using System;
using System.Globalization;
public class MainClass {
    public static void Main() {
        DateTime dt = new DateTime(2000, 1, 2);
        CultureInfo iv = CultureInfo.InvariantCulture;
        Console.WriteLine(dt.ToString(iv));            // 01/02/2000 00:00:00
        Console.WriteLine(dt.ToString("d", iv));       // 01/02/2000
    }
}

use the FromFileTime() method to convert an operating system file timestamp to a DateTime

 

using System;
class MainClass {
    public static void Main() {
        DateTime myDateTime10 = new DateTime(2004, 1, 15, 23, 2, 5);
        long myFileTime = myDateTime10.ToFileTime();        
        DateTime myDateTime11 = DateTime.FromFileTime(myFileTime);
        Console.WriteLine("DateTime.FromFileTime() = " + myDateTime11);
    }
}

use the ToFileTime() method to convert a DateTime to an operating system file timestamp

 
using System;
class MainClass {
    public static void Main() {
        DateTime myDateTime10 = new DateTime(2004, 1, 15, 23, 2, 5);
        long myFileTime = myDateTime10.ToFileTime();
        Console.WriteLine("myDateTime10.ToFileTime() = " + myDateTime10.ToFileTime());
    }
}

use the ToLongTimeString() and ToShortTimeString() methods to convert the time parts of a DateTime to long and short time strings

 
     
using System;
class MainClass {
    public static void Main() {
        DateTime myDateTime10 = new DateTime(2004, 1, 15, 23, 2, 5);
        long myFileTime = myDateTime10.ToFileTime();        
        DateTime myDateTime11 = DateTime.FromFileTime(myFileTime);
        Console.WriteLine("myDateTime11.ToLongTimeString() = " + myDateTime11.ToLongTimeString());
        Console.WriteLine("myDateTime11.ToShortTimeString() = " + myDateTime11.ToShortTimeString());
    }
}

use the ToString() method to convert a DateTime to a string

 
     
using System;
class MainClass {
    public static void Main() {
        DateTime myDateTime12 = new DateTime(2004, 1, 12, 22, 2, 10);
        Console.WriteLine("myDateTime12.ToString() = " + myDateTime12.ToString());
        Console.WriteLine("myDateTime12.ToString(\"MMMM dd, yyyy\") = " +myDateTime12.ToString("MMMM dd, yyyy"));
        Console.WriteLine("myDateTime12.ToString(\"d\") = " + myDateTime12.ToString("d"));
        Console.WriteLine("myDateTime12.ToString(\"D\") = " + myDateTime12.ToString("D"));
        Console.WriteLine("myDateTime12.ToString(\"f\") = " + myDateTime12.ToString("f"));
        Console.WriteLine("myDateTime12.ToString(\"F\") = " + myDateTime12.ToString("F"));
        Console.WriteLine("myDateTime12.ToString(\"g\") = " + myDateTime12.ToString("g"));
        Console.WriteLine("myDateTime12.ToString(\"G\") = " + myDateTime12.ToString("G"));
        Console.WriteLine("myDateTime12.ToString(\"m\") = " + myDateTime12.ToString("m"));
        Console.WriteLine("myDateTime12.ToString(\"r\") = " + myDateTime12.ToString("r"));
        Console.WriteLine("myDateTime12.ToString(\"s\") = " + myDateTime12.ToString("s"));
        Console.WriteLine("myDateTime12.ToString(\"t\") = " + myDateTime12.ToString("t"));
        Console.WriteLine("myDateTime12.ToString(\"T\") = " + myDateTime12.ToString("T"));
        Console.WriteLine("myDateTime12.ToString(\"u\") = " + myDateTime12.ToString("u"));
        Console.WriteLine("myDateTime12.ToString(\"U\") = " + myDateTime12.ToString("U"));
        Console.WriteLine("myDateTime12.ToString(\"y\") = " + myDateTime12.ToString("y"));
    }
}