I've had Time Machine enabled for the past couple of years. Thankfully, I've only really had to depend on it a couple of times but nothing major. It was set to back up everything. The only exclusion I had set was the Bootcamp partition. Due to an incident, I decided tonight to wipe my Macintosh HD partition using Disk Utility and restore from my Time Machine backup which was on a 1TB external USB hard drive. To my surprise, the oldest backup available was from July 1, 2016. Only a bit over a month old. I could swear I've had backups much older previously. Okay, no problem I thought. I only need the most recent back up anyway. I restore only to find out my "Application Support" folder, for some reason, hasn't been backed up since July 1st. But the rest of the Library folder was fine. Anyway, I just thought this has been odd. Thankfully, the July 1st backup wasn't too old and I didn't lose much at all. Otherwise, I would have lost my browser settings, bookmarks, etc. And yes, I take responsibility for not being more diligent with my back ups and should have checked before deciding to format. I just thought this was weird behavior from Time Machine.