[ntp:questions] OT: zone source file syntax

Ben Fitzgerald bmf1DELETE at ukonline.co.uk
Mon Aug 8 22:38:09 UTC 2005


I realise this is an ntp news group, but I couldn't find one for zone
info files, so here goes.

On linux I didn't have my timezone source files. On a solaris box I did
have one for europe. It has the following:

# Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
Zone    Europe/London   -0:01:15 -      LMT     1847 Dec  1
                         0:00   GB-Eire %s      1968 Oct 27
                         1:00   -       BST	1971 Oct 31 2:00u
			 0:00	GB-Eire %s	1996
			 0:00   EU      GMT/BST

# Zone  NAME            GMTOFF  RULES  FORMAT  [UNTIL]
Rule    EU   1981  max     -       Mar     lastSun  1:00u  1:00 S
Rule    EU   1996  max     -       Oct     lastSun  1:00u  0    -

As I understand it the last line of the zone means that for the present
day the EU rules should be used and that London's offset from GMT is 0.

The EU rules state:
on the last Sun of March at 01:00UTC add one hour.
on the last Sun of October at 01:00UTC do nothing.

It's the last part I don't get. I'd expect to see -1:00 here. My grasp
of this is clearly not quite right. Can help explain this?

Thanks in advance for any pointers,


Registered Linux user number 339435

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