title: Why does robocopy display some files as modified?
body: <p>I have 15+ data files I am trying to force overwrite with robocopy.  I use the following command line switches:</p>
  
  <pre><code>C:\&gt;robocopy d:\datafolder f:\backup datafile*.dat /is /fft /MT:32
  </code></pre>
  
  <p>15 files copy successfully as expected.</p>
  
  <p>I <strong>immediately</strong> run the following command hoping to see all 15 files targeted to be overwritten but 4 show a status of "modified" to be skipped.</p>
  
  <pre><code>C:\&gt;robocopy d:\datafolder f:\backup datafile*.dat /is /fft /MT:32 /v /l
  </code></pre>
  
  <p>Here is the log of both executions:</p>
  
  <blockquote>
  <pre><code>C:\&gt;robocopy d:\datafolder f:\backup datafile*.dat /is /fft /MT:32
  
  -------------------------------------------------------------------------------
     ROBOCOPY     ::     Robust File Copy for Windows
  -------------------------------------------------------------------------------
  
    Started : Thursday, December 22, 2016 11:35:45 AM
     Source : d:\datafolder\
       Dest = f:\backup\
  
      Files : datafile*.dat
  
    Options : /FFT /DCOPY:DA /COPY:DAT /IS /MT:32 /R:1000000 /W:30
  
  ------------------------------------------------------------------------------
  
  100%        New File               1.0 g        d:\datafolder\datafile0.dat
  100%        New File               1.0 g        d:\datafolder\datafile00.dat
  100%        New File               1.4 g        d:\datafolder\datafile01.dat
  100%        New File             600.0 m        d:\datafolder\datafile1.dat
  100%        New File               2.0 g        d:\datafolder\datafile11.dat
  100%        New File               2.0 g        d:\datafolder\datafile12.dat
  100%        New File               2.0 g        d:\datafolder\datafile13.dat
  100%        New File             500.0 m        d:\datafolder\datafile2.dat
  100%        New File             700.0 m        d:\datafolder\datafile3.dat
  100%        New File             500.0 m        d:\datafolder\datafile4.dat
  100%        New File             600.0 m        d:\datafolder\datafile5.dat
  100%        New File             600.0 m        d:\datafolder\datafile6.dat
  100%        New File               1.0 g        d:\datafolder\datafile7.dat
  100%        New File               1.0 g        d:\datafolder\datafile8.dat
  100%        New File               1.0 g        d:\datafolder\datafile9.dat
  
  ------------------------------------------------------------------------------
  
                 Total    Copied   Skipped  Mismatch    FAILED    Extras
      Dirs :         1         1         1         0         0         0
     Files :        15        15         0         0         0         0
     Bytes :  15.882 g  15.882 g         0         0         0         0
     Times :   1:57:36   0:09:00                       0:00:00   0:00:49
     Ended : Thursday, December 22, 2016 11:45:35 AM
  
  
  C:\&gt;robocopy d:\datafolder f:\backup datafile*.dat /is /fft /MT:32 /v /l
  
  -------------------------------------------------------------------------------
     ROBOCOPY     ::     Robust File Copy for Windows
  -------------------------------------------------------------------------------
  
    Started : Thursday, December 22, 2016 11:45:50 AM
     Source : d:\datafolder\
       Dest = f:\backup\
  
      Files : datafile*.dat
  
    Options : /FFT /V /L /DCOPY:DA /COPY:DAT /IS /MT:32 /R:1000000 /W:30
  
  ------------------------------------------------------------------------------
  
                modified           600.0 m        d:\datafolder\datafile1.dat
                modified           500.0 m        d:\datafolder\datafile2.dat
                modified           700.0 m        d:\datafolder\datafile3.dat
                modified           500.0 m        d:\datafolder\datafile4.dat
  100%        Same                   1.0 g        d:\datafolder\datafile0.dat
  100%        Same                   1.0 g        d:\datafolder\datafile00.dat
  100%        Same                   1.4 g        d:\datafolder\datafile01.dat
  100%        Same                   2.0 g        d:\datafolder\datafile11.dat
  100%        Same                   2.0 g        d:\datafolder\datafile12.dat
  100%        Same                   2.0 g        d:\datafolder\datafile13.dat
  100%        Same                 600.0 m        d:\datafolder\datafile5.dat
  100%        Same                 600.0 m        d:\datafolder\datafile6.dat
  100%        Same                   1.0 g        d:\datafolder\datafile7.dat
  100%        Same                   1.0 g        d:\datafolder\datafile8.dat
  100%        Same                   1.0 g        d:\datafolder\datafile9.dat
  
  ------------------------------------------------------------------------------
  
                 Total    Copied   Skipped  Mismatch    FAILED    Extras
      Dirs :         1         1         1         0         0         0
     Files :        15        11         4         0         0         0
     Bytes :  15.882 g  13.636 g   2.246 g         0         0         0
     Times :   0:00:00   0:00:00                       0:00:00   0:00:00
     Ended : Thursday, December 22, 2016 11:45:50 AM
  </code></pre>
  </blockquote>
  
  <p><strong>Anyone know why those 4 files are showing as modified and therefore being skipped?</strong></p>