I am a student located in Asia and I am taking Regression and Time Series this winter. I understand the exams will be held on the beginning of business days in my region - does it mean I will be taking Regression exam on my Wednesday morning (18/3) and Time Series on the next Monday morning (23/3)?

And how does the exam procedures work? NEAS will email the exam paper to my proctor?  

Desperately hope someone can help - I tried to email the NEAS admin mailbox and got no reply, but I need to confirm the schedule with my proctor asap.
[NEAS: Mary Ann at the NEAS office handles exam administration; email her or call her; she replies the same day.]

Yes, pretty much.

NEAS states that your proctor & you should plan to have the exam session at the beginning of your regular state working day, on the days specified for each exam. They clarify this on an email to your proctor as well, same time as when they send the exam to him (this should be sometime next week, if you've properly registered yourself & got the confirmation email from NEAS administrators).

FYI its not business days per se... to the best of my understanding, you WILL have to sit for your Time Series exam on Friday the 20th, regardless of whether its a holiday in your country or not.

Please however ask your proctor to respond to the email they send him next week to clarify or get a workaround for this, I might be wrong on this (but I doubt it).