Downtime report rc script?

[John]

Hi Folks,

   I'm trying to put together a simple to report at boot time how
long the system was down.

   The script itself isn't really a problem, but I'm coming up short
looking for a reliable way to determine exactly when the sytem
went down regardless of whether it was a clean reboot or a crash.

   Am I missing something simple? I've thought about writing a simple
little program to touch a file once per second invoked by the downtime
rc script after querying the last time the file was touched... but
there must be a simpler solution.

   Thoughts?

Thanks,
John