Changing File Timestamps

When digital copies documents, photographs and transparencies are made by scanning the originals they usually end up with the wrong timestamp - the instant when the digital copy was stored to disk. This can be misleading and can render the process of managing the copies difficult. Here we demonstrate how the Windows SetFileTime function can be used to redress the problem.

It should be noted that the disk file system for the parent drive where the digital copy is stored can impose constraints on the range of valid timestamps that can be assigned to the file. While timestamp data are measured in intervals of 100 nanoseconds starting from 01 January 1601, DOS file timestamps - used by FAT and FAT32 - are stored in fields that constrain them to lie between 01 January 1980 and 31 December 2099. NTFS does not impose these constraints. Hoever, you are liable to find that - although the timestamps are assigned correctly - Windows Explorer fails to display timestamps that do not lie in the 1980..2099 range.