Time Machine says it does "hourly backups for the past 24 hours, daily backups for the past month, and weekly backups for everything older than a month until the volume runs out of space". I find this confusing. If it backs up every hour, then of course, it will back up (by default) every day, week, etc. Or, does it STOP doing hourly after the first 24 hrs., then do only once daily? And then STOP doing daily after the first week, and then only back up once a week? If not, than what is the difference between hourly/daily/monthly? Please explain.