On Windows the file systems store three file dates per file: the creation date, the last modification date and the last access date.
The creation date is automatically set by the file system when a file is created in a directory. And on NTFS drives the last modification date of the directory into which a file is copied is also updated to let users know when something was modified the last time in this directory.
The last access date is also managed automatically by the file system.
The only file date which is not changed by the file system on copy is the last modification date of a file and this date is displayed usually as file date.
With Copy file dates enabled at Options - Configuration - Compare - Folder Sync - Folder Sync Options which determines the default for a new Folder Synchronization Compare sessions, respectively with Copy file dates enabled in the dialog opened via Session - Session Properties on an already opened Folder Synchronization Compare, UltraCompare sets all three dates after copying a file in target location to the source file dates if the file system on target drive (and the used protocol) supports it.
But please note that this feature is available only for a Folder Synchronization, not for a folder compare with copying files next after compare. I verified with UC v126.96.36.1996 that this option works on a folder synchronization (local NTFS to local FAT32 drive).
Some additional words on FTP folder synchronization:
On uploading a file to an FTP server the file gets on the server always the current date of the server. The FTP protocol does not support uploading files with keeping last modification date. And the FTP servers usually do not offer commands to set the file dates on server after uploading it.
On download of a file from an FTP server the file gets also the current date of the local computer. Some applications with FTP support set after the download the last modification date on local computer to the file date read before from the FTP server (with or without taking time zone difference into account), if the FTP server offers listing directories with correct file dates at all (and the user has defined the time difference between local time zone and time zone of the server).