DateTime Format In C#

• d: Represents the day of the month as a number from 1 through 31.
• dd: Represents the day of the month as a number from 01 through 31.
• ddd: Represents the abbreviated name of the day (Mon, Tues, Wed, etc).
• dddd: Represents the full name of the day (Monday, Tuesday, etc).
• h: 12-hour clock hour (e.g. 4).
• hh: 12-hour clock, with a leading 0 (e.g. 06)
• H: 24-hour clock hour (e.g. 15)
• HH: 24-hour clock hour, with a leading 0 (e.g. 22)
• m: Minutes
• mm: Minutes with a leading zero
• M: Month number(eg.3)
• MM: Month number with leading zero(eg.04)
• MMM: Abbreviated Month Name (e.g. Dec)
• MMMM: Full month name (e.g. December)
• s: Seconds
• ss: Seconds with leading zero
• t: Abbreviated AM / PM (e.g. A or P)
• tt: AM / PM (e.g. AM or PM
• y: Year, no leading zero (e.g. 2015 would be 15)
• yy: Year, leading zero (e.g. 2015 would be 015)
• yyy: Year, (e.g. 2015)
• yyyy: Year, (e.g. 2015)
• K: Represents the time zone information of a date and time value (e.g. +05:00)
• z: With DateTime values represent the signed offset of the local operating system's time zone from
  Coordinated Universal Time (UTC), measured in hours. (e.g. +6)
• zz: As z, but with leading zero (e.g. +06)
• zzz: With DateTime values represents the signed offset of the local operating system's time zone from UTC, measured in hours and minutes. (e.g. +06:00)
• f: Represents the most significant digit of the seconds fraction; that is, it represents the tenths of a second in a date and time value.
• ff: Represents the two most significant digits of the second's fraction in date and time
• fff: Represents the three most significant digits of the second's fraction; that is, it represents the milliseconds in a date and time value.
• ffff: Represents the four most significant digits of the second's fraction; that is, it represents the ten-thousandths of a second in a date and time value. While it is possible to display the ten thousandths of a second component of a time value, that value may not be meaningful.
• fffff: Represents the five most significant digits of the second's fraction; that is, it represents the hundred-thousandths of a second in a date and time value.
• ffffff: Represents the six most significant digits of the second's fraction; that is, it represents the millionths of a second in a date and time value.
• fffffff: Represents the seven most significant digits of the second's fraction; that is, it represents the ten-millionths of a second in a date and time value.

Here is a complete C# code sample that uses these formats.

using System;  
  
namespace DateTimeFormatInCSharpSample  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            // Get current DateTime. It can be any DateTime object in your code.  
            DateTime aDate = DateTime.Now;  
  
            // Format Datetime in different formats and display them  
            Console.WriteLine(aDate.ToString("MM/dd/yyyy"));  
            Console.WriteLine(aDate.ToString("dddd, dd MMMM yyyy"));  
            Console.WriteLine(aDate.ToString("dddd, dd MMMM yyyy"));  
            Console.WriteLine(aDate.ToString("dddd, dd MMMM yyyy"));  
            Console.WriteLine(aDate.ToString("dddd, dd MMMM yyyy"));  
            Console.WriteLine(aDate.ToString("dddd, dd MMMM yyyy"));  
            Console.WriteLine(aDate.ToString("dddd, dd MMMM yyyy HH:mm:ss"));  
            Console.WriteLine(aDate.ToString("MM/dd/yyyy HH:mm"));  
            Console.WriteLine(aDate.ToString("MM/dd/yyyy hh:mm tt"));  
            Console.WriteLine(aDate.ToString("MM/dd/yyyy H:mm"));  
            Console.WriteLine(aDate.ToString("MM/dd/yyyy h:mm tt"));  
            Console.WriteLine(aDate.ToString("MM/dd/yyyy HH:mm:ss"));  
            Console.WriteLine(aDate.ToString("MMMM dd"));  
            Console.WriteLine(aDate.ToString("yyyy’-‘MM’-‘dd’T’HH’:’mm’:’ss.fffffffK"));  
            Console.WriteLine(aDate.ToString("ddd, dd MMM yyy HH’:’mm’:’ss ‘GMT’"));  
            Console.WriteLine(aDate.ToString("yyyy’-‘MM’-‘dd’T’HH’:’mm’:’ss"));  
            Console.WriteLine(aDate.ToString("HH:mm"));  
            Console.WriteLine(aDate.ToString("hh:mm tt"));  
            Console.WriteLine(aDate.ToString("H:mm"));  
            Console.WriteLine(aDate.ToString("h:mm tt"));  
            Console.WriteLine(aDate.ToString("HH:mm:ss"));  
            Console.WriteLine(aDate.ToString("yyyy MMMM"));  
  
            Console.ReadKey();  
        }  
    }  
}

Above code sample generates the following output.

Here is a detailed tutorial on DateTime and formatting: Working with DateTime In C#

Learn about DateTime Class in C#

Calculate the Date Difference in C#