Are the arrival and the departure days counted as the whole days?

QUOTE,"are the arrival day counted as the whole days?"----- No; actually, so far as I know, even some Taxation instructors count the arrival day as part of 183 days. For example, you, a certain visa holder has been in the US for the whole tax year (I mean you entered the U.S. prior to January 1, 2010, Dec. 31 2009 for instance) are considered a resident alien in 2010.However, if you entered the US on Jan. 1 2010 and has been in the US for the entire year, Dec. 31, 2010, then you area nonresident alien( actually dual status alien and dual status alien is not fully resident alien but still nonresident alien.) though you meet the Substantial Presence Test (which requires presence in the U.S, for at least 183 days) during the year.


"are the the departure day counted as the whole days?"----Yes.It depends on a situation. In the case of your departure day, suppose you left the U.S. to re-establish your residence in your home country after you met the substantial presence test(>183 days in the US during 2010), then your residency termination date is generally December 31 of the year you leave. You are therefore considered a U.S. resident for the entire calendar year. However, you can bea dual status for the year you leave ( not fully resident alien but partially resident alien) "if you are not a U.S. resident during any part of the following year, and you establish that, after you left the U.S., your tax home was a foreign country and you had a closer connection to that country."