If I understood correctly, does the statement below mean that I must e-mail on Friday, November 5, 2017 but no later than 12 pm to confirm the interview or does it mean that I can e-mail earlier by the deadline, which is 12 pm on Friday, November 5, 2017?

Statement:
Please e-mail no later than 12 pm on Friday, November 5, 2017 to confirm the interview.

I think the statement above means the former (i.e I must e-mail ON Friday, November 5, 2017 but no later than 12 pm to confirm the interview). Is my understanding correct?

No. It means to email anytime before 12 pm on Friday, November 5, 2017.

Thank you!

You're welcome!

Yes, you are correct. The statement "Please e-mail no later than 12 pm on Friday, November 5, 2017 to confirm the interview" means that you must send the email to confirm the interview on Friday, November 5, 2017 before 12 pm. In other words, the deadline for sending the email is 12 pm on that day. If you send the email after 12 pm, it may be considered late and could potentially affect your interview confirmation.