How to count your US days
Checked for the 2026 tax year · Updated October 2026
Every day you’re in the US counts, even part of a day, including the days you arrive and leave. A few days don’t, such as a layover of under 24 hours between two places outside the US.
Any part of a day counts
If you were in the US at any time during a day, it counts as a full day. That includes the day you arrive and the day you leave. Drive down on January 3 and home on April 2, and that's 90 days, not 88.
Count each calendar year separately
The IRS counts January 1 to December 31. A trip from November 15 to March 31 counts partly in one year and partly in the next, so split it at New Year's.
Days that don't count
A few kinds of days are left out of the count. The ones that matter most to Canadians:
- Passing through: less than 24 hours in the US while travelling between two places outside the US, like a connecting flight to Mexico.
- Commuting to work in the US from your home in Canada, if you do it regularly.
- A medical condition that arose while you were in the US and kept you from leaving.
Short visits still count: a day of shopping in Bellingham or Buffalo is a US day.
Cruises
Days at a US port count, like any other day in the US. Days spent entirely at sea outside US waters generally don't. If cruises make up a big part of your winter, check with a cross-border professional.
Check your travel history
Not sure of your dates? US Customs and Border Protection has a free website where you can look up your US arrivals and departures, using your passport details: search for “I-94 travel history”. Your own calendar, credit card statements and travel bookings help too.
Then do the math
Add this year's days, a third of last year's and a sixth of the year before. Our day calculator does it for you, or read Do I need Form 8840?
Onward is an independent Canadian service, not the IRS. This page explains the rules in plain terms; it isn't tax or legal advice. If your situation is unusual, speak with a cross-border tax professional.