15-30 second delayed "Live" Video playback

Hey all, just wondering if this would be possible. I have never used a raspberry pi properly before and have 0 knowledge on them or their capabilities just for a bit of information. I need a way to take a live video feed from a camera or webcam, and play it back with a 15-30 second delay on an external monitor, this would need to be able to run with no internet connection and be robust enough to run for 6 hours per day, 7 days a week, 365 days a year. I'm UK based if that is of any help or hinderance. Thank you all in advance