As I understand it, TM is supposed to automatically back up hourly, then compend days into weeks. In the last month, my TM back ups have become irregular, not only not occurring hourly but sometimes skipping a day or two. Is it an coincidence that my current 3TB TM drive only has 77GB free? I know TM is supposed to delete the oldest backups to make room for the newest ones, but for business purposes, I just replace the drive. In fact, I've already got a replacement drive but haven't put it in yet figuring there was still 77GB of space left on my current drive. Is it time to replace the current TM drive and will this solve the inconsistent back up issue?