backing up new files with old modified dates

[niche]

Which batch command and switch should I use to backup a new file with a old (sometimes very old) Date Modified date in a way that avoids backing up files unnecessarily? I've been using xcopy with the /D switch in my backup.bat and just noticed it's missing my new files that have the old dates.

 

[TCG]

Take a look into Robocopy, I think you'll find it much more robust than xcopy to do what you are trying.

 

[niche]

That's what I needed. Thanks!