Hi,
I currently use a program called copywhiz on windows that backs up any files or directories created after a certain date to a usb hard drive and runs once a day.
I want to transition fully to Linux. Is there any easy to use software that works on Linux that can do this?
P.S. I have tried creating a bash script to do this but for some reason it has trouble with the date part. So a software solution would be prefered.
I'm curious to know more about your "certain date" requirement - this sounds like it might be an XY problem. As for general advanced backup programs, I have two easy recommendations that are similar in featureset:
The most important parts of real backup software IMO is the ability to compress your backups, version your files with rolling/pruning snapshots, and version your files efficiently with only deltas between them taking extra space. You can also encrypt your backup if you want to store it with a remote party, or run integrity checks to check for bitrot.
Yeah, with those options it's easier to back up your whole home directory, and then daily backups only take a minute or so and a small amount of additional space to back up what's changed since the day before.