DateTime.CompareTo Method (DateTime)

Compares the value of this instance to a specified DateTime value and returns an integer that indicates whether this instance is earlier than, the same as, or later than the specified DateTime value.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

public int CompareTo(
	DateTime value
)

Parameters

value
Type: System.DateTime

The object to compare to the current instance.

Return Value

Type: System.Int32
A signed number indicating the relative values of this instance and the value parameter.

Value

Description

Less than zero

This instance is earlier than value.

Zero

This instance is the same as value.

Greater than zero

This instance is later than value.

Implements

IComparable<T>.CompareTo(T)

This method implements the System.IComparable<T> interface and performs slightly better than the DateTime.CompareTo(Object) method overload because it does not have to convert the value parameter to an object.

Before comparing DateTime objects, make sure that the objects represent times in the same time zone. You can do this by comparing the values of their Kind properties.

The following example instantiates three DateTime objects, one that represents today's date, another that represents the date one year previously, and a third that represents the date one year in the future. It then calls the CompareTo(DateTime) method and displays the result of the comparison.

using System;

public class DateTimeComparison
{
   private enum DateComparisonResult
   {
      Earlier = -1,
      Later = 1,
      TheSame = 0
   };

   public static void Main()
   {
      DateTime thisDate = DateTime.Today;


      // Define two DateTime objects for today's date  
      // next year and last year		
      DateTime thisDateNextYear, thisDateLastYear;

      // Call AddYears instance method to add/substract 1 year
      thisDateNextYear = thisDate.AddYears(1);
      thisDateLastYear = thisDate.AddYears(-1);   

      // Compare dates 
      //
      DateComparisonResult comparison;
      // Compare today to last year
      comparison = (DateComparisonResult) thisDate.CompareTo(thisDateLastYear);
      Console.WriteLine("CompareTo method returns {0}: {1:d} is {2} than {3:d}", 
                        (int) comparison, thisDate, comparison.ToString().ToLower(), 
                        thisDateLastYear);

      // Compare today to next year
      comparison = (DateComparisonResult) thisDate.CompareTo(thisDateNextYear);
      Console.WriteLine("CompareTo method returns {0}: {1:d} is {2} than {3:d}", 
                        (int) comparison, thisDate, comparison.ToString().ToLower(), 
                        thisDateNextYear);
   }
}
// 
// If run on October 20, 2006, the example produces the following output: 
//    CompareTo method returns 1: 10/20/2006 is later than 10/20/2005 
//    CompareTo method returns -1: 10/20/2006 is earlier than 10/20/2007

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0

.NET Compact Framework

Supported in: 3.5, 2.0

XNA Framework

Supported in: 3.0, 2.0, 1.0
Was this page helpful?
(1500 characters remaining)
Thank you for your feedback

Community Additions

ADD
Show:
© 2014 Microsoft