Remove the -I part of show-messages which isn't really that useful; the

server start time can now be accessed with a new start_time format (use:
tmux display -p '#{t:start_time}')

tmux.c

@@ -44,7 +44,7 @@ struct options	*global_w_options;	/* window options */
 struct environ	*global_environ;
 
 char		*shell_cmd;
-time_t		 start_time;
+struct timeval	 start_time;
 char		 socket_path[PATH_MAX];
 
 __dead void	 usage(void);