You can now select what date dimension you use in GoodData.

Its either the 

a) Default by GoodData

b) Keboola Date Dimension - Added all week setups: Mon-Sun, Tue-Mon, Wed-Tue, Thu-Wed, Fri-Thu, Sat-Fri, Sun-Sat + Boolean value whether its weekend or working day

c) You can generate the csv file containing all necessary details and provide with GoodData 

(more info at http://wiki.keboola.com/home/keboola-connection/user-space/3-writers/gooddata/pure-gooddata-hints/custom-date-dimensions)