Glossary
FAT timestamp
The DOS date and time format (two 16-bit values, 2-second resolution) used for the created, modified and accessed times inside shell items.
A FAT (or DOS) timestamp packs a date into 16 bits (year since 1980, month, day) and a time into 16 bits (hour, minute, seconds divided by two). Seconds are therefore always even. Microsoft documents the layout with DosDateTimeToFileTime.
Shell items store the folder's modified time and, in the 0xBEEF0004 block, its created and accessed times in this format; libfwsi documents them as UTC. They describe the folder at the moment the item was recorded, not the user's visit. See ShellBags timestamps explained.