Is there enough time?

I’d like to know is whether it would be suitable to start studying for September’s SBL exam now or wait until December. The “Strategic Business Leader syllabus and study guide September 2018” downloadable from the ACCA website says. “In broad terms it is recommended that Education Providers and students should spend 50% more learning time in preparation for this examination than normally required for other exams at this level”.

I work full-time and SBL taught course by BPP starts next week which is the same time as the rest of the courses. Therefore by their calculations exam prep should take another month and a half.