[mrtg] Monitoring a target only during certain hours

[Geoff Powell]

I have an MRTG installation running here on my home network.

MRTG version is 2.10.13, running in rateup mode from cron - yes, I know
it's antediluvian, but it's the version provided by the Linux distro on
this box (Debian Sarge) - and no, I can't upgrade it, for reasons that
are beyond the scope of this post. But it works.

MRTG, as implemented, monitors 6 targets that I consider significant,
from one cron invocation. I would be open to moving the 30-day average
target to a separate invocation, if someone provides compelling reasons.
 
My ISP places a download limit of 200GB on a 30-day rolling average, and
I've worked out a way to handle that, but they recently added a clause
"we will not count data transferred between the hours of midnight and 8
a.m.".

Does anyone have an idea of how to implement this? I'm thinking "helper
script", but I don't have the least idea of how to write that script.
I'm already doing something similar for NTP, so the concept and
invocation of such scripts is familiar to me.

TIA,
-- 
Geoff Powell