[rrd-users] Showing daily average ; from midnight to midnight local time

Jean-Yves Avenard jyavenard at gmail.com
Thu Dec 10 11:06:15 CET 2009


Hi

2009/12/9 Jean-Yves Avenard <jyavenard at gmail.com>:
> I thought that another possibility would be to always store data in
> local time as if it was UTC time ; obviously twice a year it would be
> incorrect for one hour ... something I can probably live with...

Ok,

this is what I have done now...

When storing in the RRD database; I add the current time offset to the
timestamp ; set the timezone to UTC and call rrdtool update.

So as far as RRD is concerned ; midnight local = midnight UTC

When displaying the graph ; I do all my calculation as if I was in
local time ; and before calling rrdtool I add to all timestamp the
local time offset with UTC ; switch the timezone to UTC and call
rrdtool graph.

Now my daily average appears like I intended: from midnight to
midnight local time...

I've noticed some inconsistencies between daily average when I
calculate it manually between using the 5 minutes average as a basis
or the 1 hour average as a basis...

http://htpc.avenard.org/power

Thank you all for your help.
Jean-Yves



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