HBS published the following update on their admissions blog:
"We’re now turning our attention to all you Round 2 applicants. A few notes:
• The Round 2 deadline is Wednesday, January 4th at 12pm EST. Applications will not be read before that time. We never shut down the application system until every application in the process of being submitted has been received. You will receive a confirmation email from our system once it goes through.
• The office (and all of HBS) will be closed from December 23 – January 2. We will be open 8:00-5:00pm EST on both Tuesday, January 3 and Wednesday, January 4. For Round 2 applicants, there will be limited technical support available over the break at firstname.lastname@example.org. We'll also be keeping an eye on our general admissions mailbox, email@example.com, but we will not be responding on the dates HBS is closed unless we think it is critical. I will post another update here when we return after break."