When flying to and from the United States, from/until what time does it count as days of presence from an IRS tax residence standpoint?

Question

When flying to and from the United States, from/until what time does it count as days of presence from an IRS tax residence standpoint?

For example, if my plane entered the US airspace at 20:00 on May 1, landed (= touched the ground) in the US at 23:55 on May 1, that I exited the plane at 00:10 on May 2, and that I cleared the US immigration at 02:00 on May 2, then left the United States on May 3 at noon: does that count as 2 or 3 days of presence from an IRS tax residence standpoint? Same question if I exited the plane at 23:59 on May 1. Etc. Basically at what moment does the day of presence starts?

I know that from the US customs standpoint one enters the United States the moment one exits the plane, but I don't know what the IRS thinks of it.

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I understand from https://www.investopedia.com/terms/1/183-day-rule.asp (mirror) that there are some exceptions, e.g.:

Days that do not count as days of presence include:

• Days that you commute to work in the U.S. from a residence in Canada or Mexico, if you do so regularly
• Days you are in the U.S. for less than 24 hours while in transit between two other countries
• Days you are in the U.S. as a crew member of a foreign vessel
• Days you are unable to leave the U.S. because of a medical condition that develops while you are there

Answer 1

I would review what is in Publication 519 (2019), U.S. Tax Guide for Aliens as in the Introductory section there is an example on the Substantial Presence Test which includes the following section:

The term United States includes the following areas.

• All 50 states and the District of Columbia.
• The territorial waters of the United States.
• The seabed and subsoil of those submarine areas that are adjacent to U.S. territorial waters and over which the United States has exclusive rights under international law to explore and exploit natural resources.

The term does not include U.S. possessions and territories or U.S. airspace.

I'm going to make a couple of assumptions.

As you didn't mention what type of Visa or purpose of the visit, I'm going to assume a business meeting and you don't have diplomatic status.

You mention a departure from the United States on May 3. I'm going to assume back to country of origin.

• So for May 1 entering US airspace doesn't count, only when you land and as you only have less than a day on May 1, that day doesn't count.

• On May 2 you go through customs at the US airport and have that business meeting. You have now met the Substantial Presence test for May 2.

• On May 3 you leave the US at noon. That day doesn't count.

So the way I see it, you have met the Substantial Presence Test for only May 2.

The IRS has a number of pages on this matter, depending on your particular tax status:

https://www.irs.gov/individuals/international-taxpayers/foreign-earned-income-exclusion-physical-presence-test

Full Day

A full day is a period of 24 consecutive hours, beginning and ending at midnight. You must spend the full day in a foreign country or countries for that day to be counted. When you leave the United States to go to a foreign country or when you return to the United States from a foreign country, the time you spend on or over international waters does not count as time in a foreign country.

Example:

You leave the United States for France by air on June 10. You arrive in France at 9:00 a.m. on June 11. Your first full day in France is June 12.

See also: Publication 54, Tax Guide for U.S. Citizens and Resident Aliens Abroad