Time Machine works

When I design things that need to be a certain format, like lets say, a flyer. I usually just open the last flyer I made, and edit away, then save it as something else. Well sometimes I forget to hit the old SAVE AS instead of SAVE and I lose the old copy of what I was working on. Well I did that this morning, so I decided to see if Time Machine actually worked. I've been backing up copies of things for years, but I've never really needed it much, and the times I did need it, it wasn't backed up. Well I had set up mac's new software Time Machine when I bought my Mac Pro. I went digging around, and sure enough I found what I was looking for, very quickly from a backup that was created 20 minutes before my error. And there was another back up from an hour before that, and an hour before that...you get the point. Brilliant.