This is the beast mode formula, but it doesn't provide a field which can be used in the Date Range Field
DATE_FORMAT(case when (`GREG_D` >= '2017-10-29' and `GREG_D`<= '2017-11-04') then '2017-11-04'
when (`GREG_D` >= '2017-11-05' and `GREG_D`<= '2017-11-11') then '2017-11-11'
when (`GREG_D` >= '2017-11-12' and `GREG_D`<= '2017-11-18') then '2017-11-18'
when (`GREG_D` >= '2017-11-19' and `GREG_D`<= '2017-11-25') then '2017-11-25'
else ' ' end,'%m/%d/%yy')
Thanks for any ideas!