Frequency of Time Machine Backups

Discussion in 'Mac Apps and Mac App Store' started by leons, Oct 23, 2015.

  1. leons macrumors 6502

    Apr 22, 2009
    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.
  2. chrfr macrumors 604

    Jul 11, 2009
    Time Machine will purge older backups based on the pattern it describes.
  3. MacUser2525 macrumors 68000


    Mar 17, 2007
    It backs up once an hour every day a daily backup of everything that has changed since last daily backup then once a week a weekly all changes since last weekly and lastly every month a monthly backup of the changes since the last monthly.
  4. dwfaust, Oct 23, 2015
    Last edited: Oct 23, 2015

    dwfaust macrumors 601


    Jul 3, 2011
    It backs up every hour (or so, mine is actually about ever 1:10)... and keeps those backups for 24 hours. Beyond 24 hours, it only keeps ONE BACKUP (assumption is the last backup of the day) each day for the past month, then once a week all the way back.

    My available backups are:

    Every hour (approximately) from the most recent, back to yesterday at 1:15pm
    Daily backups (no timestamp) from 20OCT back to 23SEP
    Weekly backups (no timestamp) dated Thursdays from 23SEP15 back to 24APR14.
  5. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    You are mistaken. It backs up once an hour and that backup includes anything new or changed in that hour. That is all it ever backs up. The other daily, weekly, and monthly comments refer to the purging of older backups as chrfr and dwfaust explained.
  6. chabig macrumors 603

    Sep 6, 2002
    You misread it. The control panel says, "Time Machine keeps", not "does".
  7. leons thread starter macrumors 6502

    Apr 22, 2009
    GOOD CATCH! You're right. That explains a LOT! :)

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