Why does the timestamp on the directory saved on a network drive differ from the system time?

Question

MathWorks Support Team 2009-6-27

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The timestamp of files written onto a network drive do not match my system time.

For example

a = rand(100);
datestr(now),tic,save temp,toc,d=dir('temp.mat');

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Answer 1

MathWorks Support Team 2009-6-27

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When the file temp.mat is stored onto a network drive, the timestamp shown at the command prompt might not match the system time.

The discrepancy in the timestamps when saving to the network drive might be because of the limitations on the Change Notification Handles (CNHs) in Windows. MATLAB generally caches on the information that could be stored on the network drive. The changes to the directory are communicated through the Change Notification Handles. These CNHs work well on local disk. However, when using network file systems (specifically, Windows NT file systems) limitations in the file system and Windows NT limit the amount of CNH's we can use. When CNH's run out, one is unable to reliably see changes in network directories.