The time/date when Mac OS was installed

[vietluvmac]

I just wonder if there are any ways to check the date and time when the Mac OS X was installed.

I guess the system must store the information of this type somewhere, but I don't know how to mine it.

In my case, my MacBook Pro was stolen. When I found it 10 days later, the hard disk had been repartitioned and it had been installed with a fresh Yosemite version.

Now that it turns out that if I know the time/date the Yosemite was installed, I may be able to identify who is the thief.

Cheers,

 

[MacUser2525]

Open Terminal.app in the Applications/Utilities folder and look at the dates there with this command, hopefully one will give you the time (oldest you see) it was installed. As per my example here my current install dates from March 26, 2008 according to the time/date on when the obviously untouched Public folder was created.

MacUser2525:~$ ls -l
total 96
drwxr-xr-x  4 MacUser2525  admin  136B 11 Jul 09:54 Applications/
drwxr-xr-x  62 MacUser2525  admin  2.1K 16 Oct 00:25 Bin/
drwx------+  4 MacUser2525  admin  136B  8 Oct 19:57 Desktop/
drwx------+ 55 MacUser2525  admin  1.8K 16 Oct 00:24 Documents/
drwx------+  7 MacUser2525  admin  238B  2 Jul 15:19 Downloads/
drwx------+ 75 MacUser2525  admin  2.5K 27 Aug 15:34 Library/
drwx------+  9 MacUser2525  admin  306B 29 May 21:55 Movies/
drwx------+  5 MacUser2525  admin  170B 19 Jun 15:20 Music/
drwx------+ 14 MacUser2525  admin  476B 15 Oct 15:40 Pictures/
drwxr-x---+  6 MacUser2525  admin  204B 26 Mar  2008 Public/
drwxr-xr-x+  8 MacUser2525  admin  272B 11 Oct  2013 Sites/
-rw-r--r--@  1 MacUser2525  admin  2.8K 14 Oct 14:36 accounts.gpg
-rw-------  1 MacUser2525  admin  1.3K  3 Oct  2014 mbox

Edit: Now I think about it some more another way to check is the date on the
/var/db/.AppleSetupDone file it is created after the first run of the Setup Assistant and unless someone has gone out of there way to delete it so it will run again it is the date/time that machine was last setup ie. first installed.

 

[MJWMac1988]

When I found it 10 days later, the hard disk had been repartitioned and it had been installed with a fresh Yosemite version.

The creation date of the new partition should help. More specifically, check the creation and modification dates of the Home folder of the main user account, as well as of the folders inside the Home folder (such as Desktop, Documents, Music, etc.). They won't all be the same, but the most common creation and/or modification dates that fall between the date your computer was stolen and the date you got it back should be the date on which Yosemite was installed.

One way to confirm the above dates is to open the System > Library folder. Then type "install" or "log" in the search-within-a-folder search box (upper-right corner of any open window). Narrow the search down to search only the System > Library folder and file names only. The most common (numerous) creation and/or modification dates you find in this search should match the dates of your Home folder, etc. I've used this method several times over the years, and the dates have always matched with the dates that I remember installing OS X. I also know they match because I made personal log entries listing the dates on which I did those installations.

 

[chrfr]

I just wonder if there are any ways to check the date and time when the Mac OS X was installed.

I guess the system must store the information of this type somewhere, but I don't know how to mine it.

In my case, my MacBook Pro was stolen. When I found it 10 days later, the hard disk had been repartitioned and it had been installed with a fresh Yosemite version.

Now that it turns out that if I know the time/date the Yosemite was installed, I may be able to identify who is the thief.

Cheers,

In the System Information application (Apple menu, hold option key, and the first item changes from "About this Mac" to "System Information"), look under the Installations tab. The exact time and date of the OS X install will be listed there.

 

[MJWMac1988]

In the System Information application (Apple menu, hold option key, and the first item changes from "About this Mac" to "System Information"), look under the Installations tab. The exact time and date of the OS X install will be listed there.

Dang! I sure wish you had written your comment BEFORE I wrote mine!

It will be very useful information for the future. Thanks!

 

[vietluvmac]

In the System Information application (Apple menu, hold option key, and the first item changes from "About this Mac" to "System Information"), look under the Installations tab. The exact time and date of the OS X install will be listed there.

Many thanks to you. This is the absolutely simple but most convenient way.