CR period: how much is reasonable?

In order to know what could be a reasonable CR evaluation period,
could the developers subcribed to this list send in some
words of what parts of XKMS they expect to develop (client,
server, X-KISS, X-KRSS, features from proposed exit criteria)
and how much time do you expect to need to do it?

This is just for having enough arguments to justify our CR evaluation
period and what extension our charter will need.

Thanks in advance!

-jose