Convenient bump considering that I just compared the three and four month schedules. There isn't much of a differences in number of breaks: the four month schedule has 19 breaks and the three month has 15.
One of the biggest differences comes from "Re-read chapters + EK 1001 + EK Bio In-class exam" from the three month schedule being allotted two days in the four month schedule. One for the practice questions and another to re-read chapters. There are eight of those. The other comes from extra days for reviewing EK practice questions and TBR practice questions. Seven days for each for 14 additional days. These days do not otherwise exist in the three month schedule.
That gives you 22 additional days for review and 4 extra days for breaks. Given that you need to shave off 15 days from the four month schedule, you could essentially skip one break and eliminate the extra days designed for reviewing EK and TBR practice questions.