2018/5/15付のHBS Admissions Blogからの抜粋です。
https://www.hbs.edu/mba/admissions/Pages/from-the-admissions-director.aspx
For these reasons, Round 3 will no longer be an option. The spring “2+2 Round” for college seniors seeking deferred admission will remain.
So, mark your calendars! To be considered for the Harvard Business School Class of 2021, you need to apply in either Round 1 (September 5, 2018) or Round 2 (January 4, 2019). We have no preference between the two rounds — truly.
We hope that you will apply to HBS!