yum feature suggestion - also log null update time and date

I didn't see this in the  man page for yum.conf.... is there a way
to get yum to even log when yum check-update is run and there
was nothing to update?  Currently yum doesn't log "null" updates
in the yum.log but I'd like it to so I can judge better when I want to run it 
again.  I tried setting the debuglevel higher, that just increased the 
verbosity to the terminal and not the log file.

I was thinking this would likely reduce yum update repository load because
admins would look in the log file and see that it was run recently
and nothing was found.

Mark