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Speaking about the Ubuntu iso images downloadable from the official sites [1,2],
with which timezone are they saved?

Getting some info from host and whois on old-releases.ubuntu.com and releases.ubuntu.com I obtain for both:

inetnum: 91.189.88.0 - 91.189.95.255
country: GB

But even with IP location finder [3] I found

91.189.88.17 United Kingdom Scotland Douglas
91.189.88.17 United Kingdom England London
...
91.189.88.148 United Kingdom Scotland Douglas
91.189.88.148 United Kingdom England London

...so have we to suppose GMT+1 even for the date/time of the file inside?

ptetteh227
  • 1,904
Hastur
  • 3,950
  • Nice question… If the time is really reported in the local timezone, it will moreover depend on the part of the year due to daylight saving time. – Melebius Apr 26 '18 at 09:39
  • @Melebius Thx. Indeed it can depend from different factors: if you create the file on a local machine and then update it preserving the time creation or not... It should depend (or not) from the part of the world where you were... Maybe the server themselves once were somewhere else... – Hastur Apr 26 '18 at 09:47
  • I never understood the downvotes without a comment... "Tell me why you think I'm wrong and maybe I will finish to agree with you or I will enhance the question..." – Hastur Apr 26 '18 at 14:12

1 Answers1

2

In brief

The timezone of http://releases.ubuntu.com is: GMT+1. You can verify it by calculating the difference from the http and the ftp protocol of the download site.

The release process

Following the release process steps, the whole release is build on an internal server, the iso are created and updated to the cdimage server, synced with the mirrors (at present 130), and the info on the various official sites updated.

Such a complex procedure cannot prescind from a timestamp synchronization. So it should be enough to infer the info from the download server.

(Moreover the production machine seems to belong to the same owner and seems to exit on internet in the same physical node of the distribution servers.)

The http protocol listing shows:

Icon  Name                    Last modified      Size  Description
[DIR] 12.04.5/                2017-05-17 00:42    -   Ubuntu 12.04.5 LTS (Precise Pangolin)
[DIR] 12.04/                  2017-05-17 00:42    -   Ubuntu 12.04.5 LTS (Precise Pangolin)
[DIR] 14.04.5/                2017-02-16 22:30    -   Ubuntu 14.04.5 LTS (Trusty Tahr)
[DIR] 14.04/                  2017-02-16 22:30    -   Ubuntu 14.04.5 LTS (Trusty Tahr)
[DIR] 16.04.4/                2018-03-01 19:58    -   Ubuntu 16.04.4 LTS (Xenial Xerus)
[DIR] 16.04/                  2018-03-01 19:58    -   Ubuntu 16.04.4 LTS (Xenial Xerus)
[DIR] 17.10.1/                2018-01-12 05:38    -   Ubuntu 17.10 (Artful Aardvark)
[DIR] 17.10/                  2018-01-12 05:38    -   Ubuntu 17.10 (Artful Aardvark)
[DIR] 18.04/                  2018-04-06 02:17    -   Ubuntu 18.04 (Bionic Beaver)
[DIR] artful/                 2018-01-12 05:38    -   Ubuntu 17.10 (Artful Aardvark)
[DIR] bionic/                 2018-04-06 02:17    -   Ubuntu 18.04 (Bionic Beaver)
[DIR] precise/                2017-05-17 00:42    -   Ubuntu 12.04.5 LTS (Precise Pangolin)
[DIR] trusty/                 2017-02-16 22:30    -   Ubuntu 14.04.5 LTS (Trusty Tahr)
[DIR] ubuntu-core/            2016-11-03 15:30    -   
[DIR] xenial/                 2018-03-01 19:58    -   Ubuntu 16.04.4 LTS (Xenial Xerus)

The ftp protocol listing shows:

Index of /releases/
[parent directory]
Name        Size        Date Modified
12.04       0 B         2/29/12, 7:00:00 PM
12.04.5     0 B         8/6/14, 8:00:00 PM
14.04       0 B         3/26/14, 8:00:00 PM
14.04.5     0 B         8/3/16, 8:00:00 PM
16.04       0 B         2/15/17, 7:00:00 PM
16.04.4     0 B         3/1/18, 2:54:00 PM
17.10       0 B         10/18/17, 8:00:00 PM
17.10.1     0 B         1/12/18, 12:36:00 AM
18.04       0 B         4/5/18, 10:15:00 PM
FOOTER.html 22 B        1/31/06, 7:00:00 PM
HEADER.html 2.4 kB      4/6/18, 5:28:00 AM
artful/                 1/12/18,12:38:00 AM
bionic/                 4/26/18,5:00:00 PM
cdicons/                9/20/12, 8:00:00 PM
favicon.ico 1.1 kB      6/15/11, 8:00:00 PM
include/                2/7/18, 4:40:00 PM
precise/                5/16/17, 8:00:00 PM
releases                0 B 7/30/07, 8:00:00 PM
robots.txt  49 B        10/28/09, 8:00:00 PM
trusty/                 2/15/17, 7:00:00 PM
ubuntu-core/            11/2/16, 8:00:00 PM
xenial/                 3/1/18, 2:58:00 PM

The HTTP protocol shows a difference is exactly 6 hours, which matches the timezone between where I leave in US/New York and the timezone of the UK.

Check with:

http://releases.ubuntu.com/releases

versus

ftp://releases.ubuntu.com/releases

This calculate the timezone to GMT+1

From my recollection, it has usually been after 12:00PM.

Here is a thread from the official Ubuntu Site:

1 Day Left to Ubuntu Release (But in which time zone ?)

The thread isn't new, but there appears to be a lot of consistency with my recollection. I only download the LTS versions on their release date.

I read the whole thread the other day. There were some references to a timezone of the Canonical. I just tried to look for the reference in the thread, but couldn't find it for a have hour.

A view of the thread might give some perspective of time reference.

A very important component to consider (also included in the link) is:

ReleaseCandidateProcess

Pay particular attention to the last few hours of activity.

L. D. James
  • 25,036
  • Hi James, thanks for the answer, but for a quick view, they seems to discuss more about the release time in the day than about the time zone with which the file inside are signed... BTW this answer it should be useful for this question. – Hastur Apr 26 '18 at 11:05
  • I read the timezone of the official site when reading that thread yesterday. I spent a half hour trying to find the exact reference but couldn't. But I'm sure knowing the timezone of the sight won't be as significant as might be expected. There is a lot of work involved on the date of release... it's not like the clock hits and the upgrade is released. – L. D. James Apr 26 '18 at 11:42
  • I'm just noticing that you are the answer person of that thread... so you are quiet informed on what is happening. – L. D. James Apr 26 '18 at 11:43
  • Yes I understand (that's the meaning of the answer to the other page ) I was searching for a general answer, but in this question I focused on releases.ubuntu.com and old-releases.ubuntu.com (the little links in [1,2] in the question)... I suppose we have to wait for the answer of someone that update them (maybe really after the release). – Hastur Apr 26 '18 at 11:50
  • Yes this question arises because of the other one... Answering I realize that I never asked me when (time zone) those files are created... (Ok there is always the progressive numbering version, sub(sub...)version, but the question remains...) – Hastur Apr 26 '18 at 12:09
  • @Hastur I updated my answer. Hope it's more helpful. – L. D. James Apr 26 '18 at 13:35
  • Let us continue this discussion in chat. – L. D. James Apr 26 '18 at 13:44
  • Let us continue this discussion in chat. – Hastur Apr 26 '18 at 14:38