[Xymon] trimhistory error

Hi,

I'm running the trimhistory command every night to clean up the logfiles from events that happend more than a year ago using the following command:

/bin/su - xymon -c '/usr/libexec/xymon/trimhistory --cutoff=date +%s --date="today -1 year" --drop --droplogs --env=/etc/xymon/xymonserver.cfg'

Now I found out, that most of the files in the /var/lib/xymon/hist directory are corrupted and that the history of these tests are not displayed any longer on the web page. The first line of the files look like this:

Tue Jun 17 12:41:45 2014 green 1403001705Tue Jun 17 12:41:45 2014 green 1403001705 37051426

I'm not sure, but I think that the trimhistory command is responsible for that. Any ideas?

Regards, Dirk