When the daily tick marks on my graph didn’t line up with crisp changes in my data at 00:00, I realized I had a time zone issue. Rrdtool is using my local time zone (UTC+6 for instance) to choose the tick marks, while my data was converted to ticks assuming UTC+0. Is there a command line option to rrdtool graph to override the time zone?
I tried enforcing TZ=UTC+0 in the environment, but because my rrd commands are farmed out for execution I’ve had trouble making that stick.