SetLastWriteTimeUtc Method

Directory.SetLastWriteTimeUtc Method (String, DateTime)


Sets the date and time, in Coordinated Universal Time (UTC) format, that a directory was last written to.

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

public static void SetLastWriteTimeUtc(
	string path,
	DateTime lastWriteTimeUtc


Type: System.String

The path of the directory.

Type: System.DateTime

The date and time the directory was last written to. This value is expressed in UTC time.

Exception Condition

The specified path was not found.


path is a zero-length string, contains only white space, or contains one or more invalid characters. You can query for invalid characters with the GetInvalidPathChars method.


path is null.


The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters and file names must be less than 260 characters.


The caller does not have the required permission.


The current operating system is not Windows NT or later.


lastWriteTimeUtc specifies a value outside the range of dates or times permitted for this operation.

The path parameter is permitted to specify relative or absolute path information. Relative path information is interpreted as relative to the current working directory. To obtain the current working directory, see GetCurrentDirectory.

The path parameter is not case-sensitive.

For a list of common I/O tasks, see Common I/O Tasks.


These operating systems do not support this method.

The following example illustrates the differences in output when using Coordinated Universal Time (UTC) output.

// This sample shows the differences between dates from methods that use
//coordinated universal time (UTC) format and those that do not.
using System;
using System.IO;

namespace IOSamples
  public class DirectoryUTCTime
    public static void Main()
	// Set the directory.
      string n = @"C:\test\newdir";
		//Create two variables to use to set the time.
	  DateTime dtime1 = new DateTime(2002, 1, 3);
	  DateTime dtime2 = new DateTime(1999, 1, 1);

	//Create the directory.
	  catch (IOException e)

	//Set the creation and last access times to a variable DateTime value.
	  Directory.SetCreationTime(n, dtime1);
	  Directory.SetLastAccessTimeUtc(n, dtime1);

		// Print to console the results.
	  Console.WriteLine("Creation Date: {0}", Directory.GetCreationTime(n));
	  Console.WriteLine("UTC creation Date: {0}", Directory.GetCreationTimeUtc(n));
	  Console.WriteLine("Last write time: {0}", Directory.GetLastWriteTime(n));
	  Console.WriteLine("UTC last write time: {0}", Directory.GetLastWriteTimeUtc(n));
	  Console.WriteLine("Last access time: {0}", Directory.GetLastAccessTime(n));
	  Console.WriteLine("UTC last access time: {0}", Directory.GetLastAccessTimeUtc(n));

		//Set the last write time to a different value.
      Directory.SetLastWriteTimeUtc(n, dtime2);
	  Console.WriteLine("Changed last write time: {0}", Directory.GetLastWriteTimeUtc(n));
// Obviously, since this sample deals with dates and times, the output will vary
// depending on when you run the executable. Here is one example of the output:
//Creation Date: 1/3/2002 12:00:00 AM
//UTC creation Date: 1/3/2002 8:00:00 AM
//Last write time: 12/31/1998 4:00:00 PM
//UTC last write time: 1/1/1999 12:00:00 AM
//Last access time: 1/2/2002 4:00:00 PM
//UTC last access time: 1/3/2002 12:00:00 AM
//Changed last write time: 1/1/1999 12:00:00 AM


for writing to the specified file or directory. Associated enumeration: FileIOPermissionAccess.Write

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
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