Delete files older than 3 months old in a directory using .NET

Something like this outta do it.

using System.IO; 

string[] files = Directory.GetFiles(dirName);

foreach (string file in files)
{
   FileInfo fi = new FileInfo(file);
   if (fi.LastAccessTime < DateTime.Now.AddMonths(-3))
      fi.Delete();
}

For those that like to over-use LINQ.

(from f in new DirectoryInfo("C:/Temp").GetFiles()
 where f.CreationTime < DateTime.Now.Subtract(TimeSpan.FromDays(90))
 select f
).ToList()
    .ForEach(f => f.Delete());

Here's a snippet of how to get the creation time of files in the directory and find those which have been created 3 months ago (90 days ago to be exact):

    DirectoryInfo source = new DirectoryInfo(sourceDirectoryPath);

    // Get info of each file into the directory
    foreach (FileInfo fi in source.GetFiles())
    {
        var creationTime = fi.CreationTime;

        if(creationTime < (DateTime.Now- new TimeSpan(90, 0, 0, 0)))
        {
            fi.Delete();
        }
    }

The most canonical approach when wanting to delete files over a certain duration is by using the file's LastWriteTime (Last time the file was modified):

Directory.GetFiles(dirName)
         .Select(f => new FileInfo(f))
         .Where(f => f.LastWriteTime < DateTime.Now.AddMonths(-3))
         .ToList()
         .ForEach(f => f.Delete());

(The above based on Uri's answer but with LastWriteTime.)

Whenever you hear people talking about deleting files older than a certain time frame (which is a pretty common activity), doing it based on the file's LastModifiedTime is almost always what they are looking for.

Alternatively, for very unusual circumstances you could use the below, but use these with caution as they come with caveats.

CreationTime
.Where(f => f.CreationTime < DateTime.Now.AddMonths(-3))

The time the file was created in the current location. However, be careful if the file was copied, it will be the time it was copied and CreationTime will be newer than the file's LastWriteTime.

LastAccessTime
.Where(f => f.LastAccessTime < DateTime.Now.AddMonths(-3))

If you want to delete the files based on the last time they were read you could use this but, there is no guarantee it will be updated as it can be disabled in NTFS. Check fsutil behavior query DisableLastAccess to see if it is on. Also under NTFS it may take up to an hour for the file's LastAccessTime to update after it was accessed.

The GetLastAccessTime property on the System.IO.File class should help.

Basically you can use Directory.Getfiles(Path) to get a list of all the files. After that you loop through the list and call GetLastAccessTim() as Keith suggested.

you just need FileInfo -> CreationTime

and than just calculate the time difference.

in the app.config you can save the TimeSpan value of how old the file must be to be deleted

also check out the DateTime Subtract method.

good luck

Alternatively, you can use the File.GetCreationTime Method if you need to delete files based on creation dates.

An SSIS type of example .. (if this helps anyone)

          public void Main()
          {
                 // TODO: Add your code here
        // Author: Allan F 10th May 2019

        //first part of process .. put any files of last Qtr (or older) in Archive area 
        //e.g. if today is 10May2019 then last quarter is 1Jan2019 to 31March2019 .. any files earlier than 31March2019 will be archived

        //string SourceFileFolder = "\\\\adlsaasf11\\users$\\aford05\\Downloads\\stage\\";
        string SourceFilesFolder = (string)Dts.Variables["SourceFilesFolder"].Value;
        string ArchiveFolder = (string)Dts.Variables["ArchiveFolder"].Value;
        string FilePattern = (string)Dts.Variables["FilePattern"].Value;
        string[] files = Directory.GetFiles(SourceFilesFolder, FilePattern);

        //DateTime date = new DateTime(2019, 2, 15);//commented out line .. just for testing the dates .. 

        DateTime date = DateTime.Now;
        int quarterNumber = (date.Month - 1) / 3 + 1;
        DateTime firstDayOfQuarter = new DateTime(date.Year, (quarterNumber - 1) * 3 + 1, 1);
        DateTime lastDayOfQuarter = firstDayOfQuarter.AddMonths(3).AddDays(-1);

        DateTime LastDayOfPriorQuarter = firstDayOfQuarter.AddDays(-1);
        int PrevQuarterNumber = (LastDayOfPriorQuarter.Month - 1) / 3 + 1;
        DateTime firstDayOfLastQuarter = new DateTime(LastDayOfPriorQuarter.Year, (PrevQuarterNumber - 1) * 3 + 1, 1);
        DateTime lastDayOfLastQuarter = firstDayOfLastQuarter.AddMonths(3).AddDays(-1);

        //MessageBox.Show("debug pt2: firstDayOfQuarter" + firstDayOfQuarter.ToString("dd/MM/yyyy"));
        //MessageBox.Show("debug pt2: firstDayOfLastQuarter" + firstDayOfLastQuarter.ToString("dd/MM/yyyy"));


        foreach (string file in files)
        {
            FileInfo fi = new FileInfo(file);

            //MessageBox.Show("debug pt2:" + fi.Name + " " + fi.CreationTime.ToString("dd/MM/yyyy HH:mm") + " " + fi.LastAccessTime.ToString("dd/MM/yyyy HH:mm") + " " + fi.LastWriteTime.ToString("dd/MM/yyyy HH:mm"));
            if (fi.LastWriteTime < firstDayOfQuarter)
            {

                try
                {

                    FileInfo fi2 = new FileInfo(ArchiveFolder);

                    //Ensure that the target does not exist.
                    //fi2.Delete();

                    //Copy the file.
                    fi.CopyTo(ArchiveFolder + fi.Name);
                    //Console.WriteLine("{0} was copied to {1}.", path, ArchiveFolder);

                    //Delete the old location file.
                    fi.Delete();
                    //Console.WriteLine("{0} was successfully deleted.", ArchiveFolder);

                }
                catch (Exception e)
                {
                    //do nothing
                    //Console.WriteLine("The process failed: {0}", e.ToString());
                }
            }
        }

        //second part of process .. delete any files in Archive area dated earlier than last qtr ..
        //e.g. if today is 10May2019 then last quarter is 1Jan2019 to 31March2019 .. any files earlier than 1Jan2019 will be deleted

        string[] archivefiles = Directory.GetFiles(ArchiveFolder, FilePattern);
        foreach (string archivefile in archivefiles)
        {
            FileInfo fi = new FileInfo(archivefile);
            if (fi.LastWriteTime < firstDayOfLastQuarter )
            {
                try
                {
                    fi.Delete();
                }
                catch (Exception e)
                {
                    //do nothing
                }
            }
        }


                 Dts.TaskResult = (int)ScriptResults.Success;
          }

since the solutions with new FileInfo(filePath) are not easily testable, I suggest to use Wrappers for classes like Directory, File and Path like this:

public interface IDirectory
{
    string[] GetFiles(string path);
}

public sealed class DirectoryWrapper : IDirectory
{
    public string[] GetFiles(string path) => Directory.GetFiles(path);
}

public interface IFile
{
    void Delete(string path);
    DateTime GetLastAccessTime(string path);
}

public sealed class FileWrapper : IFile
{
    public void Delete(string path) => File.Delete(path);
    public DateTime GetLastAccessTimeUtc(string path) => File.GetLastAccessTimeUtc(path);
}

Then use something like this:

public sealed class FooBar
{
    public FooBar(IFile file, IDirectory directory)
    {
        File = file;
        Directory = directory;
    }

    private IFile File { get; }
    private IDirectory Directory { get; }

    public void DeleteFilesBeforeTimestamp(string path, DateTime timestamp)
    {
        if(!Directory.Exists(path))
            throw new DirectoryNotFoundException($"The path {path} was not found.");

        var files = Directory
            .GetFiles(path)
            .Select(p => new
            {
                Path = p,
                // or File.GetLastWriteTime() or File.GetCreationTime() as needed
                LastAccessTimeUtc = File.GetLastAccessTimeUtc(p) 
            })
            .Where(p => p.LastAccessTimeUtc < timestamp);

        foreach(var file in files)
        {
            File.Delete(file.Path);
        }
    }
}