Help me please with these log files

Help me please with these log files

please whats mean that on var/log/user.log
Mar 18 10:09:06 hoover RightScale: Timezone set to America/Los_Angeles
Mar 18 10:11:10 hoover RightScale: Timezone set to America/Los_Angeles
Mar 18 10:13:45 hoover RightScale: Timezone set to America/Los_Angeles
and whats mean thise line too in appache (error.log)!!!!
[Tue Apr 20 00:00:35 2010] [error] [client 193.109.122.33] request failed: error reading the headers
[Fri Apr 23 10:34:42 2010] [error] [client 193.109.122.18] request failed: error reading the headers
[Sat Apr 24 18:52:24 2010] [error] [client 193.109.122.15] request failed: error reading the headers
thank u