CX flight grading can last between 1-2 weeks, depending on which type you do. Advanced CX graders do 1 week, basic CX graders get an extra week for their Grob sorties.
KA flight grading is much more simpler than the CX one, and since the exercises for both basic and advanced are similar, KA grading almost always takes longer than CX.
Basic KA Grading (for candidates with <20 hours)
7 Flights on the Grob 115A, focuses on Basic Aircraft Control
Advanced KA Grading (for candidates with >20 hours)
7 Flights on the Grob 115A, focuses on Basic Aircraft Control (identical to the basic grading)
3 flights on CAP10 aerobatic aircraft
Anyone who knows better, please feel free to correct. In the meantime, hope this helps, good luck!