There's has been an informative discussion in CodeProject's Lounge regarding cached file dates.
Here some quotes from MSDN:
File Times A file time is a 64-bit value that represents the number of 100-nanosecond intervals that have elapsed since 12:00 A.M. January 1, 1601 (UTC). The system records file times whenever applications create, access, and write to files. Not all file systems can record creation and last access time and not all file systems record them in the same manner. For example, on NT FAT, create time has a resolution of 10 milliseconds, write time has a resolution of 2 seconds, and access time has a resolution of 1 day (really, the access date). On NTFS, access time has a resolution of 1 hour.
and in the documentation of CreateFile:
Windows NT/2000: If you rename or delete a file, then restore it shortly thereafter, Windows NT searches the cache for file information to restore. Cached information includes its short/long name pair and creation time.