Yes, you can change CTCP TIME and PING replies. (Thank you to all the people who helped me with this.) As was mentioned before, you can add your own VERSION reply, but you can't halt the default one. Here are examples of TIME and PING replies:
ctcp *:TIME:* { raw -q notice $nick : $+ $chr(1) $+ TIME $asctime(hh:nn:ss) Eastern Standard Time

$+ $chr(1) }
ctcp *:ping:*: { set %day $calc($date(dd) - 5) | ctcpreply $nick ping $ctime($date(mmmm) %day $date(yyyy) $date(HH:nn:ss)) | notice Blake $nick just pinged me | haltdef }
That PING reply is the one I just finished. It basically adds 5 days to the ping time for fun, so the person gets:
[Blake PING reply]: 120hrs 1sec
Hope that helps.