Possible to exclude older files from sync comparison?

Hi,

I wanted to try using WinSCP as a simple solution to backing up my files to an SFTP server. However, it's impractical when it has to compare every file every time - it would take days just to do the comparison, let alone the upload.

I want WinSCP to only compare files that have been modified since June. So, I do:

synchronize remote F:\Seb /incoming/winscp -criteria=time -transfer=binary -filemask=">2016-06-01 00:00:00" -preview

But it doesn't make a bit of difference... it still takes its time comparing every old file with that of the remote server. I also tried:

option exclude "<2016-06-01 00:00:00"
synchronize remote F:\Seb /incoming/winscp -criteria=time -transfer=binary -preview

Not sure if filemasks are supposed to work with option exclude, but in any case it didn't work either. I also tried the ">120D" filemask syntax to no avail.

Any suggestions on how I could limit this endless synchronize comparison? I just want simple SFTP backup that actually works.

Thanks!

WinSCP still has to list all the files to find out, if they have been modified since June.