A standard DateTime format string consists of a single format specifier character from the following table. If the format specifier is not found in the table below, a runtime exception is thrown. If the format string is longer than a single character (even if the extra characters are white spaces), the format string is interpreted as a custom format string.

Note that the result string produced by these format specifiers are influenced by the settings in the Regional Options control panel. Computers with different cultures or different date and time settings will generate different result strings.

The date and time separators displayed by format strings are defined by the DateSeparator and TimeSeparator characters associated with the DateTimeFormat property of the current culture. However, in cases where the InvariantCulture is referenced by the 'r', 's', and 'u' specifiers, the characters associated with the DateSeparator and TimeSeparator characters do not change based on the current culture.

The following table describes the standard format specifiers for formatting the DateTime object.

The following example illustrates how to use the standard format strings with DateTime objects.

[Visual Basic]
Dim dt As DateTime = DateTime.Now
Dim dfi As DateTimeFormatInfo = New DateTimeFormatInfo()
Dim ci As CultureInfo = New CultureInfo("de-DE")

' Make up a new custom DateTime pattern, for demonstration.
dfi.MonthDayPattern = "MM-MMMM, ddd-dddd"

' Use the DateTimeFormat from the culture associated 
' with the current thread.

Console.WriteLine( dt.ToString("d") )  
Console.WriteLine( dt.ToString("m") )

' Use the DateTimeFormat from the specific culture passed.
Console.WriteLine( dt.ToString("d", ci ) )

' Use the settings from the DateTimeFormatInfo object passed.
Console.WriteLine( dt.ToString("m", dfi ) )

' Reset the current thread to a different culture.
Thread.CurrentThread.CurrentCulture = New CultureInfo("fr-BE")
Console.WriteLine( dt.ToString("d") )
[C#]
DateTime dt = DateTime.Now;
DateTimeFormatInfo dfi = new DateTimeFormatInfo();
CultureInfo ci = new CultureInfo("de-DE");

// Make up a new custom DateTime pattern, for demonstration.
dfi.MonthDayPattern = "MM-MMMM, ddd-dddd";

// Use the DateTimeFormat from the culture associated 
// with the current thread.
Console.WriteLine( dt.ToString("d") );  
Console.WriteLine( dt.ToString("m") );

// Use the DateTimeFormat from the specific culture passed.
Console.WriteLine( dt.ToString("d", ci ) );

// Use the settings from the DateTimeFormatInfo object passed.
Console.WriteLine( dt.ToString("m", dfi ) );

// Reset the current thread to a different culture.
Thread.CurrentThread.CurrentCulture = new CultureInfo("fr-BE");
Console.WriteLine( dt.ToString("d") );