[rrd-users] Re: X-grid problems

[Alex van den Bogaerdt]

On Tue, Nov 01, 2005 at 11:16:49AM +0100, Erik Versaevel - InfoPact Netwerkdiensten wrote:
> Someone on #rrdtool pointed out to me that this might be daylightsavingtime related, Europe switched on sunday 30-10

Yeah, at 01:00 UTC to be precise.
See http://www.vandenbogaerdt.nl/rrdtool/summertime.php for how things
look when all is right.

It displays its labels at a fixed interval, in your case of 24 hours.
Sunday 00:00 METDST + 24hrs equals sunday 23:00 MET.  That's sunday
twice, as your case shows.  It does indeed look weird.

It is a displaying problem, not a data problem so I wouldn't worry
about it too much if I were you.  It will go away as soon as all
summertime has disappeared from your graph.

I do seem to recall that in the past, rrdtool would display its
labels like so:

  |  |  |  |  |  |  |  |  |  |  ...... |  |  |  |  |  |  |   ...
22:00 00:00 02:02:00 04:00 06:00 ... 20:00 22:00 00:00 02:00 ...
(summertime to normal time, overlapping 02:00 twice)

  |  |  |  |  |  |  |  |  |  |  ...... |  |  |  |  |  |  |   ...
22:00 00:00    04:00 06:00 08:00 ... 22:00 00:00 02:00 04:00 ...
(normal time to summertime, missing 02:00 as there is none)

I may not be 100% right here but the key factor is that it would
continue to show local time plus a fixed interval. This means
midnight would be at the right place, labels in your case would
have been correct.  But it would require fixing those other two
problems I just show.  Anyway, I'm just guessing here but I think
this is why the new method is being used.

HTH
-- 
Alex van den Bogaerdt
http://www.vandenbogaerdt.nl/rrdtool/

--
Unsubscribe mailto:rrd-users-request at list.ee.ethz.ch?subject=unsubscribe
Help        mailto:rrd-users-request at list.ee.ethz.ch?subject=help
Archive     http://lists.ee.ethz.ch/rrd-users
WebAdmin    http://lists.ee.ethz.ch/lsg2.cgi