The time required depends on your own pace and your own method of studying. Personally I would suggest giving it time between 15 to 20 days if you have planned on studying for 6 to 7 months in entirety.

I assume that you are talking here about the compulsory subject of Pakistan Affairs, and not the optional subject of Indo-Pak History.

Your study plan also depends on what your optional subjects are and how much of the syllabus of Pak Affairs would overlap with other subjects. If you have chosen subjects like US History/ Histoy of India and Pak/International Affairs you will notice that some topics under Pak Affairs overlap with these. As a result the syllabus will become less of a burden.

I would also like to highlight a tip I learned from the 2019 topper Shanza Faiq, who said that she had hardly two months to prepare for CSS so she skipped the history in Pakistan Affairs and studied from post-partition onward i.e. 1947 - present. Furthermore, a quick look at the past papers from 2017 till 2020 will show that most of the lonq questions in Pakistan Affairs deal not with history of Pakistan but are generalized questions about Pakistan's recent situation. I suggest you don't spend too much time on pre-partition history, based on my personal experience.

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