Csharp/CSharp Tutorial/Date Time/DateTime

Add seconds to current time

<source lang="csharp">using System; using System.Collections.Generic; using System.ruponentModel; using System.Data; using System.Drawing; public class MainClass{

  public static void Main(){
       DateTime endTime = DateTime.Now.AddSeconds(123);
       while (DateTime.Now < endTime)
       {
           Console.WriteLine(DateTime.Now.TimeOfDay.ToString());
       }
  }

}</source>

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^CTerminate batch job (Y/N)? n

Benchmark Timing with DateTime

<source lang="csharp">using System; using System.Collections.Generic; using System.Text;

  public class MyMath
  {
     public int DoSum( int n )
     {
        int result = 0;
        for ( int i = 1; i <= n; i++ )
        {
           result += i;
        }
        return result;
     }
     public int DoSum2()
     {
        return 1 + 20;
     }
  }
  public class TestDriver
  {
     public static void Main()
     {
        int val = 20;  
        int iterations = 1000000;
        int result = 0;
        MyMath m = new MyMath();
        DateTime startTime = DateTime.Now;
        for ( int i = 0; i < iterations; i++ )
        {
           result = m.DoSum( val );
        }
        TimeSpan elapsed =DateTime.Now - startTime;
        Console.WriteLine("Loop: Sum of ({0}) = {1}",val, result );
        Console.WriteLine(elapsed.TotalMilliseconds.ToString() );
        startTime = DateTime.Now;
        for ( int i = 0; i < iterations; i++ )
        {
           result = m.DoSum2();
        }
        elapsed = DateTime.Now - startTime;
        Console.WriteLine("Brute Force: Sum of ({0}) = {1}",val, result );
        Console.WriteLine(elapsed.TotalMilliseconds );
     }
  }</source>

Create a DateTime instance, specifying the number of ticks

<source lang="csharp">using System; class MainClass {

 public static void DisplayDateTime(string name, DateTime myDateTime) {
   Console.WriteLine(name + " = " + myDateTime);
   Console.WriteLine(name + ".Year = " + myDateTime.Year);
   Console.WriteLine(name + ".Month = " + myDateTime.Month);
   Console.WriteLine(name + ".Day = " + myDateTime.Day);
   Console.WriteLine(name + ".Hour = " + myDateTime.Hour);
   Console.WriteLine(name + ".Minute = " + myDateTime.Minute);
   Console.WriteLine(name + ".Second = " + myDateTime.Second);
   Console.WriteLine(name + ".Millisecond = " + myDateTime.Millisecond);
   Console.WriteLine(name + ".Ticks = " + myDateTime.Ticks);
 }
 public static void Main()
 {
   
   DateTime myDateTime4 = new DateTime(0);
   DisplayDateTime("myDateTime4", myDateTime4);
 }

}</source>

myDateTime4 = 01/01/0001 12:00:00 AM
myDateTime4.Year = 1
myDateTime4.Month = 1
myDateTime4.Day = 1
myDateTime4.Hour = 0
myDateTime4.Minute = 0
myDateTime4.Second = 0
myDateTime4.Millisecond = 0
myDateTime4.Ticks = 0

Create a DateTime instance, specifying the year, month, and day

<source lang="csharp">using System; class MainClass {

 public static void DisplayDateTime(string name, DateTime myDateTime) {
   Console.WriteLine(name + " = " + myDateTime);
   Console.WriteLine(name + ".Year = " + myDateTime.Year);
   Console.WriteLine(name + ".Month = " + myDateTime.Month);
   Console.WriteLine(name + ".Day = " + myDateTime.Day);
   Console.WriteLine(name + ".Hour = " + myDateTime.Hour);
   Console.WriteLine(name + ".Minute = " + myDateTime.Minute);
   Console.WriteLine(name + ".Second = " + myDateTime.Second);
   Console.WriteLine(name + ".Millisecond = " + myDateTime.Millisecond);
   Console.WriteLine(name + ".Ticks = " + myDateTime.Ticks);
 }
 public static void Main()
 {
   
   int year = 2002;
   int month = 12;
   int day = 25;
   DateTime myDateTime = new DateTime(year, month, day);
   DisplayDateTime("myDateTime", myDateTime);
 }

}</source>

myDateTime = 25/12/2002 12:00:00 AM
myDateTime.Year = 2002
myDateTime.Month = 12
myDateTime.Day = 25
myDateTime.Hour = 0
myDateTime.Minute = 0
myDateTime.Second = 0
myDateTime.Millisecond = 0
myDateTime.Ticks = 631763712000000000

Create a DateTime instance, specifying the year, month, day, and JulianCalendar object

<source lang="csharp">using System; class MainClass {

 public static void DisplayDateTime(string name, DateTime myDateTime) {
   Console.WriteLine(name + " = " + myDateTime);
   Console.WriteLine(name + ".Year = " + myDateTime.Year);
   Console.WriteLine(name + ".Month = " + myDateTime.Month);
   Console.WriteLine(name + ".Day = " + myDateTime.Day);
   Console.WriteLine(name + ".Hour = " + myDateTime.Hour);
   Console.WriteLine(name + ".Minute = " + myDateTime.Minute);
   Console.WriteLine(name + ".Second = " + myDateTime.Second);
   Console.WriteLine(name + ".Millisecond = " + myDateTime.Millisecond);
   Console.WriteLine(name + ".Ticks = " + myDateTime.Ticks);
 }
 public static void Main()
 {
   int year = 2002;
   int month = 12;
   int day = 25;
   int hour = 23;
   int minute = 30;
   int second = 12;
   int millisecond = 5;
   DateTime myDateTime = new DateTime(year, month, day, hour, minute, second, millisecond);
   DisplayDateTime("myDateTime", myDateTime);
   
   System.Globalization.JulianCalendar myCalendar = new System.Globalization.JulianCalendar();
   DateTime myDateTime3 = new DateTime(year, month, day, myCalendar);
   DisplayDateTime("myDateTime3", myDateTime3);
 }

}</source>

myDateTime = 25/12/2002 11:30:12 PM
myDateTime.Year = 2002
myDateTime.Month = 12
myDateTime.Day = 25
myDateTime.Hour = 23
myDateTime.Minute = 30
myDateTime.Second = 12
myDateTime.Millisecond = 5
myDateTime.Ticks = 631764558120050000
myDateTime3 = 07/01/2003 12:00:00 AM
myDateTime3.Year = 2003
myDateTime3.Month = 1
myDateTime3.Day = 7
myDateTime3.Hour = 0
myDateTime3.Minute = 0
myDateTime3.Second = 0
myDateTime3.Millisecond = 0
myDateTime3.Ticks = 631774944000000000

Create a DateTime instance, specifying the year, month, day, hour, minute, second, and millisecond

<source lang="csharp">using System; class MainClass {

 public static void DisplayDateTime(string name, DateTime myDateTime) {
   Console.WriteLine(name + " = " + myDateTime);
   Console.WriteLine(name + ".Year = " + myDateTime.Year);
   Console.WriteLine(name + ".Month = " + myDateTime.Month);
   Console.WriteLine(name + ".Day = " + myDateTime.Day);
   Console.WriteLine(name + ".Hour = " + myDateTime.Hour);
   Console.WriteLine(name + ".Minute = " + myDateTime.Minute);
   Console.WriteLine(name + ".Second = " + myDateTime.Second);
   Console.WriteLine(name + ".Millisecond = " + myDateTime.Millisecond);
   Console.WriteLine(name + ".Ticks = " + myDateTime.Ticks);
 }
 public static void Main()
 {
   int hour = 23;
   int minute = 30;
   int second = 12;
   int millisecond = 5;
   int year = 2004;
   int month = 5;
   int day = 12;
   DateTime myDateTime = new DateTime(year, month, day, hour, minute, second, millisecond);
   DisplayDateTime("myDateTime", myDateTime);
 }

}</source>

myDateTime = 12/05/2004 11:30:12 PM
myDateTime.Year = 2004
myDateTime.Month = 5
myDateTime.Day = 12
myDateTime.Hour = 23
myDateTime.Minute = 30
myDateTime.Second = 12
myDateTime.Millisecond = 5
myDateTime.Ticks = 632200014120050000

Create a DateTime with the current date and time

<source lang="csharp">using System; class MainClass {

   public static void Main(string[] args)
   {
       DateTime now = DateTime.Now;
       Console.WriteLine("Now   : {0}", now);
   }

}</source>

Now   : 25/03/2007 2:10:52 PM

Create a TimeSpan instance, and add it to DateTime

<source lang="csharp">using System; class MainClass {

 public static void DisplayDateTime(string name, DateTime myDateTime) {
   Console.WriteLine(name + " = " + myDateTime);
   Console.WriteLine(name + ".Year = " + myDateTime.Year);
   Console.WriteLine(name + ".Month = " + myDateTime.Month);
   Console.WriteLine(name + ".Day = " + myDateTime.Day);
   Console.WriteLine(name + ".Hour = " + myDateTime.Hour);
   Console.WriteLine(name + ".Minute = " + myDateTime.Minute);
   Console.WriteLine(name + ".Second = " + myDateTime.Second);
   Console.WriteLine(name + ".Millisecond = " + myDateTime.Millisecond);
   Console.WriteLine(name + ".Ticks = " + myDateTime.Ticks);
 }
 public static void Main()
 {
   
   DateTime myDateTime4 = new DateTime(0);
   TimeSpan myTimeSpan = new TimeSpan(4, 12, 10);
   myDateTime4 += myTimeSpan;
   DisplayDateTime("myDateTime4", myDateTime4);
   
   
 }

}</source>

myDateTime4 = 01/01/0001 4:12:10 AM
myDateTime4.Year = 1
myDateTime4.Month = 1
myDateTime4.Day = 1
myDateTime4.Hour = 4
myDateTime4.Minute = 12
myDateTime4.Second = 10
myDateTime4.Millisecond = 0
myDateTime4.Ticks = 151300000000

Create a TimeSpan representing 1 week and subtract from a DataTime

<source lang="csharp">using System; class MainClass {

   public static void Main(string[] args)
   {
       TimeSpan oneWeek = new TimeSpan(4, 12, 0, 0) + new TimeSpan(2, 12, 0, 0);
           
       DateTime now = DateTime.Now;
       // Create a DateTime representing 1 week ago.
       DateTime past = now - oneWeek;
       
       Console.WriteLine("Past  : {0}", past);
   
   }

}</source>

Past  : 18/03/2007 2:10:53 PM

Creating specific date/times: year, month, day, hour, minute, second

<source lang="csharp">using System; using System.Collections.Generic; using System.Globalization; using System.IO; using System.Text; using System.Security.Cryptography; public class MainClass {

   public static void Main()
   {
       DateTime dt1 = new DateTime(2004, 10, 19);
       Console.WriteLine("dt1: {0}", dt1);
       DateTime dt2 = new DateTime(2004, 10, 19, 22, 47, 35);
       Console.WriteLine("dt2: {0}", dt2);
       DateTime dt3 = new DateTime(2004, 10, 19, 22, 47, 35, 259);
       Console.WriteLine("dt3: {0}", dt3);
   }

}</source>

dt1: 19/10/2004 12:00:00 AM
dt2: 19/10/2004 10:47:35 PM
dt3: 19/10/2004 10:47:35 PM

Display the Date, Day, DayOfWeek, DayOfYear, Ticks, and TimeOfDayProperties of DateTime

<source lang="csharp">using System; class MainClass {

 public static void Main()
 {
   
   DateTime myDateTime = DateTime.Now;
   Console.WriteLine("myDateTime.Date = " + myDateTime.Date);
   Console.WriteLine("myDateTime.Day = " + myDateTime.Day);
   Console.WriteLine("myDateTime.DayOfWeek = " + myDateTime.DayOfWeek);
   Console.WriteLine("myDateTime.DayOfYear = " + myDateTime.DayOfYear);
   Console.WriteLine("myDateTime.Ticks = " + myDateTime.Ticks);
   Console.WriteLine("myDateTime.TimeOfDay = " + myDateTime.TimeOfDay);

 }

}</source>

myDateTime.Date = 25/03/2007 12:00:00 AM
myDateTime.Day = 25
myDateTime.DayOfWeek = Sunday
myDateTime.DayOfYear = 84
myDateTime.Ticks = 633104295802812500
myDateTime.TimeOfDay = 14:26:20.2812500

Use the AddYears(), AddMonths(), AddDays(), AddMinutes(), and AddSeconds() methods to add periods to a DateTime

<source lang="csharp">using System; class MainClass {

 public static void Main()
 {
   DateTime myDateTime9 = new DateTime(2004, 1, 1);
   Console.WriteLine("Initial myDateTime9 = " + myDateTime9);
   myDateTime9 = myDateTime9.AddYears(1);
   myDateTime9 = myDateTime9.AddMonths(5);
   myDateTime9 = myDateTime9.AddDays(3);
   myDateTime9 = myDateTime9.AddMinutes(30);
   myDateTime9 = myDateTime9.AddSeconds(15);
   Console.WriteLine("Final myDateTime9 = " + myDateTime9);
 }

}</source>

Initial myDateTime9 = 01/01/2004 12:00:00 AM
Final myDateTime9 = 04/06/2005 12:30:15 AM

Use the Compare() method to compare DateTime instances

<source lang="csharp">using System; class MainClass {

 public static void Main()
 {
   DateTime myDateTime3 = new DateTime(2004, 1, 13);
   DateTime myDateTime4 = new DateTime(2004, 1, 14);
   Console.WriteLine("myDateTime3 = " + myDateTime3);
   Console.WriteLine("myDateTime4 = " + myDateTime4);
   int intResult = DateTime.rupare(myDateTime3, myDateTime4);
   Console.WriteLine("DateTime.rupare(myDateTime3, myDateTime4) = " + DateTime.rupare(myDateTime3, myDateTime4));
 }

}</source>

myDateTime3 = 13/01/2004 12:00:00 AM
myDateTime4 = 14/01/2004 12:00:00 AM
DateTime.rupare(myDateTime3, myDateTime4) = -1

Use the DaysInMonth() method to retrieve the number of days in a particular month and year

<source lang="csharp">using System; class MainClass {

 public static void Main()
 {
   int days = DateTime.DaysInMonth(2004, 1);
   Console.WriteLine("DateTime.DaysInMonth(2004, 1) = " + days);
 }

}</source>

DateTime.DaysInMonth(2004, 1) = 31

Use the Equals() method to compare DateTime instances

<source lang="csharp">using System; class MainClass {

 public static void Main()
 {
   DateTime myDateTime3 = new DateTime(2004, 1, 13);
   DateTime myDateTime4 = new DateTime(2004, 1, 14);
   Console.WriteLine("myDateTime3 = " + myDateTime3);
   Console.WriteLine("myDateTime4 = " + myDateTime4);
   
   
   bool boolResult = DateTime.Equals(myDateTime3, myDateTime4);
   Console.WriteLine("DateTime.Equals(myDateTime3, myDateTime4) = " + boolResult);
   boolResult = myDateTime3.Equals(myDateTime4);
   Console.WriteLine("myDateTime3.Equals(myDateTime4) is " + boolResult);
 }

}</source>

myDateTime3 = 13/01/2004 12:00:00 AM
myDateTime4 = 14/01/2004 12:00:00 AM
DateTime.Equals(myDateTime3, myDateTime4) = False
myDateTime3.Equals(myDateTime4) is False

Use the FromFileTime() method to convertan operating system file timestamp to a DateTime

<source lang="csharp">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);
 }

}</source>

DateTime.FromFileTime() = 15/01/2004 11:02:05 PM

Use the IsLeapYear() method to determine if a particular year is a leap year

<source lang="csharp">using System; class MainClass {

 public static void Main()
 {
   bool boolResult = DateTime.IsLeapYear(2004);
   Console.WriteLine("DateTime.IsLeapYear(2004) = " + boolResult);
 }

}</source>

DateTime.IsLeapYear(2004) = True

Use the Now and UtcNow properties to get the currrent date and time

<source lang="csharp">using System; class MainClass {

 public static void Main()
 {
   
   Console.WriteLine("DateTime.Now = " + DateTime.Now);
   Console.WriteLine("DateTime.UtcNow = " + DateTime.UtcNow);
   DateTime myDateTime = DateTime.Now;
   Console.WriteLine("myDateTime = " + myDateTime);
   DateTime myDateTime2 = DateTime.UtcNow;
   Console.WriteLine("myDateTime = " + myDateTime);
 }

}</source>

DateTime.Now = 25/03/2007 2:26:19 PM
DateTime.UtcNow = 25/03/2007 9:26:19 PM
myDateTime = 25/03/2007 2:26:19 PM
myDateTime = 25/03/2007 2:26:19 PM

Use the overloaded addition operator (+) to add a TimeSpan to a DateTime

<source lang="csharp">using System; class MainClass {

 public static void Main()
 {
   
   DateTime myDateTime = DateTime.Parse("1/11/2004 23:10:30");
   
   TimeSpan myTimeSpan = new TimeSpan(1, 2, 4, 10);
   DateTime myDateTime8 = myDateTime + myTimeSpan;
   Console.WriteLine("myDateTime + myTimeSpan = " + myDateTime8);
 }

}</source>

myDateTime + myTimeSpan = 03/11/2004 1:14:40 AM

Use the overloaded less than operator (

<source lang="csharp">using System; class MainClass {

 public static void Main()
 {
   DateTime myDateTime3 = new DateTime(2004, 1, 13);
   DateTime myDateTime4 = new DateTime(2004, 1, 14);
   Console.WriteLine("myDateTime3 = " + myDateTime3);
   Console.WriteLine("myDateTime4 = " + myDateTime4);
   
   bool boolResult = myDateTime3 < myDateTime4;
   Console.WriteLine("myDateTime3 < myDateTime4 is " +  boolResult);
 }

}</source>

myDateTime3 = 13/01/2004 12:00:00 AM
myDateTime4 = 14/01/2004 12:00:00 AM
myDateTime3 < myDateTime4 is True

Use the overloaded subtraction operator (-) to subtract a TimeSpan from a DateTime

<source lang="csharp">using System; class MainClass {

 public static void Main()
 {
   
   DateTime myDateTime = DateTime.Parse("1/11/2004 23:10:30");
   
   TimeSpan myTimeSpan = new TimeSpan(1, 2, 4, 10);
   DateTime myDateTime8 = myDateTime - myTimeSpan;
   Console.WriteLine("myDateTime - myTimeSpan = " + myDateTime8);
 }

}</source>

myDateTime - myTimeSpan = 31/10/2004 9:06:20 PM

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

<source lang="csharp">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());
 }

}</source>

myDateTime10.ToFileTime() = 127187101250000000