Counting Winters in Arizona Down to the Day

The situation

'How many days can I actually spend in Arizona before this becomes a problem?' Trevor asked that question in the first phone call, and it turned out to be the right question asked several years too late. He managed a department at a hospital in the Hamilton area, a demanding, full-time role that anchored him firmly in Ontario for most of the year. But for three consecutive winters he and his wife Anahit had rented the same condominium near Phoenix, arriving earlier each year as his tolerance for Ontario winters declined and his accumulated vacation time grew.

Anahit worked part time and could extend her stays more freely than Trevor could. Their son Aram, a veterinarian who had also relocated south for a stretch during one of those winters to help run a relative's clinic, complicated the travel pattern further, since family visits meant occasional overlapping trips that were not always logged with any care. Nobody had been counting days with the discipline the situation required. Trevor assumed that as long as he did not become a full-time resident of Arizona, nothing would change.

That assumption was wrong in two directions at once. The Canada Revenue Agency opened a residency review after a routine data match flagged an extended absence pattern, questioning whether Trevor had in fact given up Ontario residency during his longest winter away. Almost simultaneously, correspondence arrived suggesting that Trevor's cumulative presence in the United States over a rolling three-year period might meet the threshold that treats a person as a US tax resident regardless of citizenship or immigration status, a test built on a weighted count of days present in the current and two preceding years.

Trevor had not kept a day log. He had boarding passes for some trips, condo booking records for others, and gaps he could only estimate. The amount in dispute, once both authorities' preliminary positions were laid out side by side, ran into the low-to-mid six figures, driven mostly by the Canadian side's suggestion that Trevor's centre of vital interests had shifted south during his longest winter stretch. He needed one reconstruction that would satisfy both governments without contradicting itself.

The problem

The core difficulty was that Canada and the United States measure presence differently, and a day count built for one authority does not automatically answer the other. The US test looks at a weighted average of days present over the current year and the two years before it, counting all of the current year's days, a third of the prior year's, and a sixth of the year before that. Cross a set threshold under that formula and a person can be treated as a US resident for tax purposes even without a green card or citizenship, unless a treaty-based exception or a closer-connection claim applies.

Canada's test is different again. Residency turns on residential ties — a home available for use, a spouse or dependants in the country, social and economic connections — weighted as a whole rather than counted mechanically. An extended absence does not by itself end Canadian residency, but a lengthening pattern of winters away, combined with a rented base abroad and a spouse who travelled even more, was exactly the kind of fact pattern that invites a residency review.

Layered onto both questions was a slower-moving complication that neither Trevor nor his team controlled: the US filing that would formally document a closer-connection exception, and the corresponding paperwork on the Canadian side, both required processing through government channels that were running well behind normal turnaround times that year. Every substantive step in the file had to wait on a queue neither side could jump, which meant the day-count dispute stayed open for far longer than the underlying facts alone would have justified.

The stakes were real on both sides. If the US position held, Trevor could face US tax filing obligations layered on top of his Canadian ones, with limited relief for tax already paid unless the treaty exception was properly claimed and accepted. If the Canadian position held instead, he risked being treated as a non-resident for a stretch of years, triggering a deemed disposition of his investment portfolio and other capital property at fair market value on the date residency was found to have ended. The home itself would not have been part of that exposure — Canadian real estate is specifically excluded from the deemed-disposition rule on emigration and stays taxable here regardless of where the owner lives — but the rest of his non-registered holdings would have been caught. The two outcomes were not just different amounts — they were different legal universes, and Trevor's uneven travel records did not clearly rule either one out.

What we did

1. Rebuilt the day count from primary sources first. We started with the hardest evidence available — flight records, credit card statements showing location-tagged purchases, and the condominium's booking and access logs — rather than relying on memory, because a day count challenged later needed to survive scrutiny from two separate authorities with different incentives to dispute it. The result was a working calendar for all three years that Trevor could not have produced on his own, built from records a skeptical reviewer would find credible rather than from recollection alone.
2. Cross-checked the reconstruction against Anahit's and Aram's travel separately. Their overlapping trips had blurred Trevor's own memory of specific dates, so we treated each traveller's record independently and only merged the data once each account was internally consistent on its own terms, rather than assuming family members who travelled together always crossed the border on the same day. That discipline caught several dates Trevor had misremembered by a week or more, some of which would have shifted a borderline year over the US threshold if left uncorrected.
3. Ran the US weighted-day formula against the reconstructed calendar. This told us, with actual numbers rather than impressions, whether Trevor was over or under the threshold in each of the three years in question, and by how much — a calculation that turned out to matter because he was over in one year and comfortably under in the other two.
4. Prepared the closer-connection filing for the year that exceeded the threshold. Where the weighted count came in over the line, we assembled documentation showing Trevor's stronger and more permanent ties to Canada — his continuous employment, the home he maintained year-round, and his Ontario healthcare coverage — because the exception exists for someone whose real life stayed anchored in one country despite a heavy travel year. It gave the US authority a concrete basis to treat him as exempt despite the day count.
5. Addressed the Canadian residency review on its own terms. We did not treat the US filing as an answer to the Canadian question, since the two tests are not mirror images of each other and a document built for one authority does not automatically satisfy the other's standard. Instead we assembled a separate package on residential ties showing Trevor's home, employment, and family connections in Ontario had remained continuous throughout, giving the CRA reviewer a picture built for the actual test being applied.
6. Managed the file through an extended processing delay. Once both packages were filed, progress depended entirely on government queues moving at their own pace rather than on anything further we could argue or submit. We set a realistic expectation with Trevor early so the wait did not feel like neglect, checked in at set intervals rather than repeatedly, and used the waiting period productively to tighten the documentation for the years still under discussion so the file was stronger, not just older, by the time either authority responded.
7. Negotiated a settlement position once initial responses came back. When neither authority accepted the full record without qualification, we opened a negotiation on the weakest year rather than relitigating the whole three-year span, since spending further time defending a year where the day count genuinely exceeded the threshold risked delaying resolution on the two years that were already strong. The approach aimed to concede the one year genuinely open to dispute in exchange for closing the other two cleanly, which is what ultimately happened.

The outcome

The result was not a clean win, and we told Trevor that early rather than late. The Canadian residency review closed with his ongoing residency confirmed for all three years — his Ontario ties were simply too continuous to support a finding otherwise, and that part of the file resolved in his favour without much friction. The US side was harder. The one year where his weighted day count genuinely exceeded the threshold did not fully clear on the closer-connection argument; the authority accepted a reduced position rather than the full exemption, on the basis that his presence pattern that particular year had gone beyond what the exception was designed to cover.

Trevor ended up filing a limited US return for that single year and paying tax on a portion of income for the period in question, a result that landed toward the lower end of the amount originally in dispute rather than anywhere near the top. It was a compromise both sides could live with rather than a vindication of his original position, and it cost him real money and a season of stress he had not budgeted for.

What changed afterward mattered as much as what the file resolved. Trevor now keeps a running day log for every winter trip, cross-checked twice a year, and he and Anahit coordinate their travel dates deliberately rather than by preference. Aram's overlapping visits are now logged separately from the start. The dispute cost time and money that better records would have avoided entirely, and Trevor has said as much himself — the question he should have asked before the first extended winter was the one he eventually asked three years too late.

What you can learn from this