Comparing date

I have:

select  ClientNo, ClientFName, ClientLName, PsychSocialCognitiveDate, ????
from PsychSocialCognitive, Demo
where ClientNo = ClientNumberPsychSocialCognitive
      and PsychSocialCognitiveDate > '01/01/1900'
order by ClientLName, ClientFName

What I want to compare is if
1) PsychSocialCognitiveDate is within 6 months from now (=today) or
2) PsychSocialCognitiveDate is within 12 months (= 1 year) from now (=today)  or
3) PsychSocialCognitiveDate is over 1 year from now (=today)

The output, along with ClientNo, ClientFName, ClientLName, should say:

1) if PsychSocialCognitiveDate is within 6 months from now
    'Yes' with the number of days passed under 'Within 6 months' column
2) if PsychSocialCognitiveDate is within 12 months (= 1 year) from now
    'Yes' with the number of days passed under Within 12 months' column
3) if PsychSocialCognitiveDate is over 1 year from now
    'Yes' with the number of days passed under 'Over 1 Year' column

i.e.

ClientNo  ClientFName ClientLName  PsychSocialCognitiveDate  < 6 months < 12 months  >1 year
741            John                  Doe                      2005-12-12                                                        yes(398)
723            Ethel                Dorko                     2005-08-19                                                        yes (423)
bla....

( ) -> the number of days elapsed from now (today).

thx