Firstly, thanks for your great WinSCP software. It's been a tremendous help.
I usually synchronize a folder with an FTP server with modification time as a comparison criteria. This works great for a while until daylight saving time (i.e. summer time) came a few weeks ago. After DST comes, basically all files are declared different because the 1 hour offset. I thought it was a trivial glitch and copied all files in the folder to a local folder. However, this happens again and again. The local files are always 1 hour offset from the remote ones. So, I think it's a bug.