[monit] monitor checksum and timestamp

[Matthias Teege]

Moin,

I need to backup configuration files after changes. 

check file fluff_conf with path /etc/fluff.conf
  if changed checksum
      then exec "/bin/backup fluff.conf"

works for this but if I make small changes the file was copied any two
minutes. What I need is something like this:

check file fluff_conf with path /etc/fluff.conf
  if changed checksum and timestamp > 30 Minutes
      then exec "/bin/backup fluff.conf"

How do I config monit for that problem?

Many thanks
Matthias