Software To Automatically Upload Files to FTP?

I have some important files on a few of my servers that I backup every 2-3 hours (Financial, POS, etc). I use Acronis Backup & Restore for my Servers and Quickbooks Built-In Backup Feature. However, I keep those files backed up to an external drive but now I am wanting to keep another copy online. I have a few websites with good hosting plans so I am planning on using those hosting accounts for storage. Is there some type of software that I can use to automatically transfer the contents of specific folders to an FTP Server online? Basically I'll choose the folders and set a time to transfer the contents. It would be a plus if the software does not transfer files that haven't changed or that it already transferred.