questions on time fencing examples; -c mode

[djw1149]

the dnsdbq man page has examples:

 # only responses after Aug 22, 2015 (midnight)
 $ dnsdbq ... -A 2015-08-22
 # only responses before Jan 22, 2013 (midnight)
 $ dnsdbq ... -B 2013-01-22
 # only responses from 2015 (midnight to midnight)
 $ dnsdbq ... -B 2016-01-01 -A 2015-01-01
 # only responses after 2015-08-22 14:36:10
 $ dnsdbq ... -A "2015-08-22 14:36:10"
 # only responses from the last 60 minutes
 $ dnsdbq ... -A "-3600"
 # only responses after "just now"
 $ dnsdbq -f ... -A "-3600"
 # batch mode with only responses after "just now", even if feeding inputs
 to dnsdbq in batch mode takes hours.
 $ date +%s
 1485284066
 $ dnsdbq ... -A 1485284066

Maybe the word "only" implies we should be using -c strict mode? Should we add -c to the text or change "only responses" to "responses that include "?

Separately, a user requests that we explain that:

• -c can only be specified once,
• -c makes both ends of the time expression strict, and
• maybe say that having one side strict and one side loose is not as valuable a use case so is not supported?