FolderMatch relies on file date/times when comparing two files. By comparing the last modified date/times of two files, it determines which of the two is more recent.

 

A file date/time is a value representing the number of 100-nanosecond intervals that have elapsed since 12:00 A.M. January 1, 1601 Coordinated Universal Time (UTC). The system records file times when applications create, access, and write to files.

 

The NTFS file system stores time values in UTC format, so they are not affected by changes in time zone or daylight saving time. The FAT file system stores time values based on the local time of the computer. For example, a file that is saved at 3:00pm PST in Washington is seen as 6:00pm EST in New York on an NTFS volume, but it is seen as 3:00pm EST in New York on a FAT volume.

 

Timestamps are updated at various times and for various reasons. The only guarantee about a file time stamp is that the file time is correctly reflected when the handle that makes the change is closed.

Not all file systems can record creation and last access times, and not all file systems record them in the same manner. For example, the resolution of create time on FAT is 10 milliseconds, while write time has a resolution of 2 seconds and access time has a resolution of 1 day, so it is really the access date. The NTFS file system delays updates to the last access time for a file by up to 1 hour after the last access.

 

 

 

When the program compares folder contents, it uses the file's last modified date to determine whether a file is newer or older than its counterpart in the other folder. Therefore, the last modified dates must be correct. If the internal clock on a PC is incorrect or inoperative, any time a file is date stamped, the stamp will be incorrect. Comparing this file’s date with another file’s date could cause unreliable results.

 

For best results, ensure that the computer clock’s time is correct and functioning properly on all computers that will use FolderMatch. To assist you with this, we provide a tool that will set your system clock to the correct time. We recommend that you use this tool every so often to ensure that your system clock maintains accurate time.

 

Note: In this help document, we will freely use the terms file date, file time, & file time stamp when discussing file date/times. The terms are more or less interchangeable.