A standard date and time format string uses a single format specifier to define the text representation of a date and time value. Any date and time format string that contains more than one character, including white space, is interpreted as a custom date and time format string; for more information, see Custom Date and Time Format Strings. A standard or custom format string can be used in two ways:
To define the string that results from a formatting operation.
To define the text representation of a date and time value that can be converted to a DateTime or DateTimeOffset value by a parsing operation.
Standard date and time format strings can be used with both DateTime and DateTimeOffset values.
Tip
You can download the Formatting Utility, an application that enables you to apply format strings to either numeric or date and time values and displays the result string.
The following table describes the standard date and time format specifiers. Unless otherwise noted, a particular standard date and time format specifier produces an identical string representation regardless of whether it is used with a DateTime or a DateTimeOffset value