[mythtv-users] timezone on FE and BE not the same (but they are!)

Michael T. Dean mtdean at thirdcontact.com
Thu Oct 6 02:37:28 UTC 2011

On 10/05/2011 02:45 AM, Brian J. Murrell wrote:
> My newly crafted frontend machine, built on v0.25pre-3437-gaa38944 is
> whining:
> 2011-10-05 02:39:55.516952 C  Time zone settings on the master backend
> differ from those on this system.
> 2011-10-05 02:39:55.516975 N  Detected time zone settings:
>      Master: Zone ID: 'America/Toronto', UTC Offset: '-14400', Current
> Time: '2011-10-05T02:39:55'
>       Local: Zone ID: 'Etc/UTC', UTC Offset: '-14400', Current Time:
> '2011-10-05T02:39:55'
> Yet the /etc/localtime file on both machines is identical:
> frontend# md5sum /etc/localtime
> 78936ec75f504c9df36e5454e9770c9b  /etc/localtime
> backend# md5sum /etc/localtime
> 78936ec75f504c9df36e5454e9770c9b  /etc/localtime
> Both of which match a different FE around here that's working just fine:
> other_frontend# md5sum /etc/localtime
> 78936ec75f504c9df36e5454e9770c9b  /etc/localtime
> All of which are the same as:
> frontend# md5sum /usr/share/zoneinfo/America/Toronto
> 78936ec75f504c9df36e5454e9770c9b  /usr/share/zoneinfo/America/Toronto
> So what the h-e-double-hockey-sticks is going on here with this new FE?

Either your frontend is not using /etc/localtime to set its time zone...

Time zone can be overridden with TZ environment variable (i.e. 

Different distros use different approaches for specifying/configuring 
time zone, so if, perhaps, you recently switched distros, you may not 
have configured it properly/fully for your new distro.

Or, for some reason, someone overwrote /usr/share/zoneinfo/Etc/UTC with 
a copy of /usr/share/zoneinfo/America/Toronto...

$ md5sum /usr/share/zoneinfo/Etc/UTC
c79354b8dbee09e62bbc3fb544853283  /usr/share/zoneinfo/Etc/UTC

I'm guessing yours gives 78936ec75f504c9df36e5454e9770c9b...  This 
generally occurs become some brain-dead distro decides to use a symlink 
for /etc/localtime that points to the local zone file (i.e. ln -s 
/usr/share/zoneinfo/Etc/UTC /etc/localtime ) instead of placing a copy 
of Etc/UTC at /etc/localtime (it makes for a lean, mean distro--it saves 
a whole 118 *bytes*!!!).  Then when a user tries to set the proper time 
using the command line (rather than GUI config tools), they do a sudo cp 
/usr/share/zoneinfo/America/Toronto /etc/localtime , and, since 
/etc/localtime is pointing to /usr/share/zoneinfo/Etc/UTC , the user 
ends up copying America/Toronto on top of Etc/UTC.  Then they may notice 
the new time zone didn't take, and eventually end up actually deleting 
the /etc/localtime symlink and then copying America/Toronto to 
/etc/localtime, and the new time zone "takes" and they think all is 
well--not knowing they "corrupted" their zone files...


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