Hi Saya.
The real answer to your question goes beyond how many days you should spend and depends on multiple things, the most significant of them being the difference between your practice test verbal section scores and your verbal section score goal.
Also, how you are doing in answering each type of verbal question, SC, CR and RC, figures into what you would be best served by doing over the next 20 days.
Meanwhile, your quant performance so far and quant score goal are factors as well.
So to help us to answer your question, maybe you could tell us more about how verbal has been going for you, what you goal for the verbal section is, and how your quant prep and GMAT prep overall have been going.
