How to create date related elseif calculated field in tableau if I want to put a filter on dates. For example I want to segment my dates in my back end data like this :-

case

when STAY_DT between '01-JAN-2013' and '29-JAN-2012' then 'P1'

when STAY_DT between '30-JAN-2012' and '26-FEB-2012' then 'P2'

when STAY_DT between '27-FEB-2012' and '01-APR-2012' then 'P3'

when STAY_DT between '02-APR-2012' and '29-APR-2012' then 'P4'

when STAY_DT between '30-APR-2012' and '27-MAY-2012' then 'P5'

when STAY_DT between '28-MAY-2012' and '01-JUL-2012' then 'P6'

when STAY_DT between '02-JUL-2012' and '29-JUL-2012' then 'P7'

when STAY_DT between '30-JUL-2012' and '26-AUG-2012' then 'P8'

when STAY_DT between '27-AUG-2012' and '30-SEP-2012' then 'P9'

when STAY_DT between '01-OCT-2012' and '28-OCT-2012' then 'P10'

when STAY_DT between '29-OCT-2012' and '25-NOV-2012' then 'P11'

when STAY_DT between '26-NOV-2012' and '31-DEC-2012' then 'P12'

when STAY_DT between '01-JAN-2013' and '27-JAN-2013' then 'P1'

when STAY_DT between '28-JAN-2013' and '24-FEB-2013' then 'P2'

when STAY_DT between '25-FEB-2013' and '31-MAR-2013' then 'P3'

when STAY_DT between '01-APR-2013' and '28-APR-2013' then 'P4'

when STAY_DT between '29-APR-2013' and '26-MAY-2013' then 'P5'

when STAY_DT between '27-MAY-2013' and '30-JUN-2013' then 'P6'

when STAY_DT between '01-JUL-2013' and '28-JUL-2013' then 'P7'

when STAY_DT between '29-JUL-2013' and '25-AUG-2013' then 'P8'

when STAY_DT between '26-AUG-2013' and '29-SEP-2013' then 'P9'

when STAY_DT between '30-SEP-2013' and '27-OCT-2013' then 'P10'

when STAY_DT between '28-OCT-2013' and '24-NOV-2013' then 'P11'

when STAY_DT between '25-NOV-2013' and '31-DEC-2013' then 'P12'

else 'KC'

end as PERIOD,

Any assistance is appreciated.