-B 0 and -A 0 are silently ignored

[reedjc]

-A 0 -B 0 -c
results in:
error: -c without -A or -B makes no sense.
Using either -A or -B without -c is just silently ignored.
Looking at manual it requires a positive number when in that format. And code checks for != 0.
0 could be valid is as in show all first seen since epoch but not really important.
Its just the error output is misleading.
This is low priority.