Any Part of a Day: The Rule That Ruins Careful Plans

The plan gets built the same way every time. Somebody works out that the threshold is 183 days, decides to stay under it, and starts counting. Nights in the old state, mostly. Weekends flagged. A cushion of a week or two at the end of the year in case something comes up. It is a reasonable plan, it is built on a real number, and the person building it is doing more work than most people ever do.

Then it turns out that the unit being counted is not the one they were counting. In New York, and in a specific list of other jurisdictions, a day is not a night. It is not twelve hours. It is not the majority of your waking time. Under 20 NYCRR 105.20, "presence within New York State for any part of a calendar day constitutes a day spent within New York State." A four-hour lunch is a day. A connecting flight that lands and takes off is a day, in most cases. Driving to the airport counts, or does not count, depending on a distinction we will get to.

And the arithmetic that follows from that sentence is what actually breaks the plan. Arrive at 11 p.m. on a Sunday, leave at 6 a.m. on Monday, and you have spent seven hours in New York and two days. One night became two days. Do that twenty times in a year and you have spent forty days against your budget while sleeping in the state twenty times. A person counting nights and a person counting calendar days can look at the same year and be forty days apart.

This article is informational and is not legal or tax advice. Day-count rules vary by jurisdiction and the details matter a great deal; work through your own facts with a qualified CPA or tax attorney.

The first thing worth knowing is that this is not an aggressive reading by an auditor. It is a regulation that was litigated and upheld.

New York’s December 2021 Nonresident Audit Guidelines, the 107-page manual the Tax Department writes for its own auditors, sets it out directly: "The description of a day in New York is not defined by statute. Section 105.20 of the New York Personal Income Tax regulations, however, states that 'presence within New York State for any part of a calendar day constitutes a day spent within New York State.' This regulation was challenged in Leach v Chu, 150 AD2d 842, and upheld by the Appellate Division. Thus, any part of a day spent in New York State, for whatever reason (business or pleasure), would count as a day toward the 183-day rule, even if the taxpayer comes into New York and leaves on the same day."

For whatever reason, business or pleasure. There is no purpose test on the front end. The question is presence, not what you were doing.

The guidelines then say something that reads, at first, like relief. "The literal interpretation of 'any part of a day' could mean stepping over the state line for one second; however, no audit is ever expected to be based on such a minimal amount of time spent in New York. Common sense must prevail." That is a real statement of audit policy and it is worth knowing. It is also immediately qualified in the next sentence: "That being said, presence in New York for brief periods of time would normally constitute days in the state."

Read those two sentences together and you get the actual posture. Nobody is going to build a case on you crossing a bridge and turning around. Everybody is going to count the afternoon you spent in the city.

The case that shows where the line really falls involves no business, no apartment use, and no attempt to game anything. It involves errands.

In Matter of John and Patricia D. Klingenstein, DTA No. 815156, the taxpayers lived in Connecticut near the New York border. They came into New York on 21 days in 1989 and 22 days in 1990, for shopping and dining. Those days were counted, and the taxpayers were held to be statutory residents of New York as a result. The Administrative Law Judge explained why in a passage that is quoted in the state’s own audit manual: "There is, unfortunately, no shopping or dining exception in the statute, regulation, or caselaw. In fact, the recognized exceptions stand in contrast to purposeful presence in the State. Here, petitioners’ presence in New York on the border days was not an in-transit presence, and was not unintended, unavoidable, unplanned, inadvertent or involuntary. Rather, petitioners’ presence was purposeful and voluntary."

Unintended, unavoidable, unplanned, inadvertent, involuntary. That is the vocabulary of the exceptions, and it tells you what they are for. They exist for days that happened to you. They do not exist for days you chose, however ordinary the choice.

There is a second point buried in the same chapter that people consistently miss. The guidelines state that "the statutory residency rules do not require that the taxpayer utilize the New York place of abode on every day that New York presence is demonstrated. The 183-day rule and the permanent place of abode test are separate and distinct factors in determining statutory residence." Your apartment can be in Manhattan and your day can be in Buffalo. It still counts. The abode prong and the day prong are tested independently, and satisfying neither one alone is what keeps you out.

New York recognizes exactly two categories of presence that do not produce a day. Both are worth understanding precisely, because the version people carry in their heads is much wider than the version in the manual.

The travel exception comes from 20 NYCRR 105.20(c) itself, which disregards presence that is solely for "boarding a plane, ship, train or bus for travel to a destination outside New York State, or while traveling through New York State to a destination outside New York State." The guidelines work the two branches separately: boarding a conveyance for a destination outside the state, so a Connecticut resident driving to JFK to fly to Europe does not spend a New York day, and continuing travel, begun outside the state, by "automobile, plane or train" to a point outside the state.

What decides the close cases is not the length of the stop. The manual names two criteria: "(1) whether the traveler’s activity is incidental to his presence for travel purposes and (2) the degree of control the taxpayer exercises over his travel arrangements." Control is the hinge. As the guidelines put it, "someone who arrives a day early for a cruise, in order to attend a business meeting, would be present for that day, whereas time spent by someone who visits a friend during an unavoidable delay or stopover would not count as a day present in New York." The delay you did not choose is forgiven. The early arrival you scheduled is not.

Inside a genuine travel day, ordinary friction does not spoil it. The manual is specific and generous here: "the purchase of meals or other items at a terminal, access to an automatic teller machine (ATM), stopping for gas or a meal while driving through New York, stopping to pick up a traveling companion on route to the terminal, parking the car in New York in order to meet a limousine or other conveyance that takes the individual to the airport or terminal should not change the treatment of this day as a travel day."

The medical exception is narrower than its reputation. It comes from Stranahan v State Tax Commission, 68 AD2d 250, 416 NYS2d 836 (3d Dept 1979), where the Appellate Division held that when a nondomiciliary seeks treatment for a serious illness, time spent in a medical facility for that treatment should not count. New York then went further than the case required, and the guidelines say so: "it is Audit policy that confinement to a medical institution for any reason in New York (serious or otherwise), does not constitute a day spent in New York." The manual gives the example of someone who has a heart attack while in the state on business and cannot be removed.

The word doing the work is confinement. In Matter of Ralph and Leona Kern, 240 AD2d 969, the Appellate Division sustained a finding of New York City statutory residency and rejected the argument that days spent in the city as an outpatient or visiting doctors fell under Stranahan, finding the contention "to be lacking in merit." And in Matter of Dr. Charles F. Brush III and The Estate of Ellen S. Brush, DTA No. 817204, the question was whether a husband’s days visiting his hospitalized wife could be excluded. The ALJ concluded they could not: "there appears to be no basis upon which to treat Mrs. Brush’s hospital days as non-New York City days for petitioner, and petitioner has not pointed to any such clear basis for doing so." Being in a hospital bed is an exception. Sitting beside one is not.

Now take one concrete trip and run it through three states, because this is where the assumption that a rule is a rule does the most damage. The trip: you land at 11 p.m., sleep, and leave at 1 p.m. the following afternoon. Fourteen hours, one night, two calendar dates.

In New York, that is two days. Any part of a calendar day, twice.

In Maryland, it is one. Administrative Release No. 37 defines the unit this way: "A ‘day’ is defined to mean any part of a day, provided, however, that a continuous period of 24 hours or less may not constitute more than one day." Maryland adopts the same any-part-of-a-day premise and then caps it, so a single unbroken stretch of a day or less can never be charged twice. That proviso is a genuinely different rule, and over a year of frequent short trips it is the difference between comfortably clear and comfortably over.

In Minnesota, if the two points on either end of that stop are both outside Minnesota, it may be zero. Minn. R. 8001.0300, subpart 4, states that "a person shall be treated as present in Minnesota on any day if the person is physically present in Minnesota at any time during that day," and then carves out transit: a person in transit between two points outside Minnesota who is physically present in Minnesota less than 24 hours will not be treated as present on any day during that transit. The rule supplies its own worked example. Someone flying from New York to California who changes flights in Minnesota, arriving at 7:00 P.M. on March 1 and departing at 1:00 P.M. on March 2, counts neither March 1 nor March 2. Note what makes it work: both endpoints outside the state, and under 24 hours. Change the destination to a Minneapolis meeting and both days come back.

One trip. Two days, one day, or none, depending entirely on which state’s regulation you happen to be standing in.

People carry 183 around as though it were a national constant. It is not even a constant among the three states in this article.

New York requires more than 183 days. The regulation frames the taxpayer’s own recordkeeping duty around proving they "did not spend more than 183 days" in the state, and the audit guidelines describe the taxpayer’s burden as showing "that they spent less than 184 days in New York." Exactly 183 does not trigger the test. Day 184 does.

Minnesota is a day tighter, and this is the single most common miss in the state. Minn. Stat. section 290.01, subdivision 7(b), defines a resident to also mean an individual domiciled outside the state "who maintains a place of abode in the state and spends in the aggregate more than one-half of the tax year in Minnesota," with military service and reciprocity as the only carve-outs, and adds that "presence within the state for any part of a calendar day constitutes a day spent in the state. Individuals shall keep adequate records to substantiate the days spent outside the state." The Department of Revenue translates the threshold on its own 183-day rule page as spending "at least 183 days in Minnesota during the year. Any part of a day counts as a full day." At least, not more than. ResidencyIQ’s Minnesota dossier lists this among the state’s most common exit mistakes in plain terms: landing at exactly 183 days physically present, not realizing Minnesota’s threshold is "at least," not "more than."

Maryland runs a two-prong test where both prongs must be satisfied, and states the day threshold inclusively. Under Tax-General Article section 10-101(k) and COMAR 03.04.02.01B, as summarized in Administrative Release No. 37, an individual is a Maryland resident if domiciled in Maryland on the last day of the taxable year, "or if the individual maintains a place of abode in Maryland for more than six months of the taxable year and is physically present in the State for 183 days or more during the taxable year." Maryland also tells you what the abode prong is not meant to reach: "If a residence is used for the purpose of a vacation home or for the purpose of returning to Maryland to visit family and friends, then the individual cannot be considered a resident of this State unless they are physically present in the State for 183 days or more of the taxable year."

Three states, three boundaries. In New York, 183 is safe. In Minnesota and Maryland, 183 is the trigger. If you built a plan around the number without checking which side of it your state sits on, you built the plan around a coin flip.

ResidencyIQ maintains a dossier for each of the 56 US jurisdictions, and one of the fields in every dossier records what that jurisdiction says about partial days. Reading the field across all 56 produces a picture that is less like a rule and more like a scatter.

Fourteen jurisdictions state the any-part-of-a-day standard affirmatively in a statute, a regulation, or published department guidance: California, Georgia, Idaho, Maine, Maryland, Massachusetts, Minnesota, New York, Washington, and the five territories, American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the US Virgin Islands. Five more, Arizona, Connecticut, New Jersey, Rhode Island, and Wisconsin, apply it in practice without publishing guidance as granular as New York’s.

Four jurisdictions measure something other than a calendar day. Utah’s current administrative rule, R865-9I-2, implementing Utah Code section 59-10-136, defines the unit for the 183-or-more-day test as "a day in which the individual spends more time in this state than in any other state." That is a majority-of-day standard, and it is the opposite of New York’s. It also supersedes the Tax Commission’s older 1997 advisory opinion 97-016, which had read the prior statute to mean that a fraction of a calendar day counted as a whole day, so anyone working from a decade-old memory of Utah has the wrong rule.

Ohio does not count days at all. Under Ohio Revised Code section 5747.24, the unit is a contact period: an individual "has one contact period in this state if the individual is away overnight from the individual’s abode located outside this state and while away overnight from that abode spends at least some portion, however minimal, of each of two consecutive days in this state." Away overnight is itself defined loosely, as being away from the outside-Ohio abode "for a continuous period of time, however minimal, beginning at any time on one day and ending at any time on the next day." The statutory presumption of non-Ohio domicile runs to no more than 212 contact periods, so both the unit and the number differ from every state discussed above.

Idaho is the outlier worth studying, because it writes an escape hatch directly into the counting rule. Idaho Code section 63-3013 defines a resident to include an individual who "maintains a place of abode in this state for the entire taxable year and spends in the aggregate more than two hundred seventy (270) days of the taxable year in this state," and then provides that "presence within the state for any part of a calendar day shall constitute a day spent in the state unless the individual can show that his presence in the state for that day was for a temporary or transitory purpose." New York gives you two enumerated exceptions. Idaho gives you a general standard you can argue. The threshold is also 270, not 183.

Thirteen jurisdictions have no answer because the question does not arise: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, and Wyoming impose no individual income tax on wage and investment income, and Illinois, Iowa, Kansas, Mississippi, and South Carolina set no bright-line statutory-residency day threshold for a taxpayer to cross, resolving residency through domicile instead. Days still get reconstructed in those states as evidence of domicile; there is simply no number to stay under.

That leaves 20 income-tax jurisdictions with a time-based residency test and no published answer to the question of what a day is: Alabama, Arkansas, Colorado, Delaware, Hawaii, Indiana, Kentucky, Louisiana, Michigan, Missouri, Montana, Nebraska, New Mexico, North Carolina, North Dakota, Oklahoma, Oregon, Pennsylvania, Vermont, and West Virginia. Their statutes set a threshold, in days or in months, and simply never define the unit. In practice these states reconstruct presence from third-party records once a question is raised, and the taxpayer discovers what the convention is during the audit rather than before it. If you are planning around a threshold in one of those 20, the honest position is that the denominator of your calculation is unsettled, which is an argument for a wider margin rather than a narrower one.

The people this rule catches most often are not doing anything exotic. They are driving south in November and north in April, and the drive itself is where the count goes wrong.

Consider a Minnesota winter departure. If the trip runs Minneapolis to Naples, the origin end is not transit between two points outside Minnesota, so Minn. R. 8001.0300’s carve-out does nothing for the departure day. It is a Minnesota day. The same is true in reverse in April. Two travel days a year is trivial; the pattern that is not trivial is the person who flies back six or eight times over the winter for a board meeting, a grandchild, a closing, or a doctor, each round trip contributing two calendar days at minimum and often three. Someone moving from Minnesota to Florida is leaving a jurisdiction that ResidencyIQ’s dossiers rate at the top of the scale for both audit aggressiveness and exit stickiness, and whose Supreme Court, in Larson v. Commissioner of Revenue, 824 N.W.2d 329 (Minn. 2013), upheld a residency finding against a taxpayer who had claimed Nevada residency since 1998, for tax years 2002 through 2006.

The Maryland version has a different shape because of the 24-hour proviso. A Marylander moving from Maryland to Florida who returns for tight overnight visits gets those charged as single days rather than pairs, which materially changes the arithmetic of frequent short trips. But Maryland pairs an inclusive 183-day threshold with a six-month abode prong and a domicile analysis in which, per Administrative Release No. 37, "the two most important criteria in determining a person’s domicile are where the person lives and where the person is registered to vote." The day count is only one of the two prongs, and clearing it does not end the inquiry if domicile never actually moved.

New York is the strictest of the three on both dimensions, no proviso and two enumerated exceptions, and for someone moving from New York to Florida the count is very close to the whole statutory residency case. It is also the state where undocumented days hurt most: the taxpayer carries the burden by clear and convincing evidence, and a day you cannot account for is not a neutral day.

There is one piece of comfort in the New York manual that snowbirds should know about, because it is the rare instruction that runs the taxpayer’s way. On weekend days at home in the domicile state, where people rarely generate receipts, the guidelines tell auditors that "in such situations, auditors should generally accept the taxpayer’s allegations absent evidence to the contrary such as a clear pattern of regularly being in New York on weekends." Absent a pattern. Establish the pattern and the concession disappears.

And Florida contributes nothing to any of this on its own account, which is the part that surprises people. Florida has no individual income tax, no statutory day-count test, and no residency audit to pass. Every day you count while claiming Florida is being counted for the benefit of the state you left. What Florida does have is a cross-check running the other direction: county property appraisers verify homestead exemptions against driver license and voter registration data and out-of-state resident filings, and Fla. Stat. section 196.161 allows recapture of an improperly claimed exemption for any year within the prior ten, with a penalty of 50 percent of the unpaid taxes for each year and 15 percent interest per year.

Count calendar dates, not nights. This is the single change that closes most of the gap. Every date on which you set foot in the state is a candidate day, and a trip that spans midnight is two candidates. If your working number comes from a list of nights, it is understated, and probably by more than you would guess.

Build the margin at the top, not the bottom. A plan that lands on 180 in a state with an inclusive 183-day threshold has three days of room, and three days is roughly one unplanned funeral. Decide what number you are actually managing to, and make it far enough from the threshold that a single emergency does not decide the year.

Prove the travel days as travel days while you can. A day that qualifies under the transit exception looks identical, in a bank statement, to a day you spent in the state. What separates them is the itinerary: the boarding pass showing the onward leg, the ticket showing both endpoints outside the state, the timestamps showing under 24 hours. Save those at the time. Reconstructing an airline itinerary from three years ago is a different and worse project than saving it the week you flew.

Document medical confinement specifically. Where a medical exception exists, it turns on confinement to a facility, and the record that supports it is an admission and discharge record, not a memory. Where the care was outpatient, do not assume the exception applies; in New York it does not.

Check your own count before someone else does. Mobility map day tracking records days and nights across states as the year happens, against each jurisdiction’s own threshold, so the number you are managing to is a live one rather than an estimate you built in January. The value of doing it contemporaneously is not tidiness. It is that a discrepancy found in March is a question you can still answer, and the same discrepancy found in an audit two years later is a day the state gets to assign.

And know which rule your state actually uses before you optimize against it. New York, Maryland, Minnesota, Utah, Ohio, and Idaho are six jurisdictions with six materially different answers to the question of what a day is, and 20 more have never published one. The number 183 is the least state-specific thing about any of these tests.

The Mobility Map records days and nights across states as they happen, measured against each jurisdiction’s own day-count threshold, so a year is counted while it is being lived rather than reconstructed after a notice arrives. Evidence Vault holds the travel itineraries, financial records, and residence documents that turn a claimed travel day into a demonstrated one. AuditIQ surfaces thin days and retained-tie exposure, and advisor sharing lets a CPA or tax attorney review the chronology directly.

ResidencyIQ organizes records and highlights potential exposure factors. It is not a law firm or an accounting firm and does not provide legal or tax advice; work with a qualified CPA or tax attorney on your own residency change or audit.

New York State Department of Taxation and Finance, Nonresident Audit Guidelines (December 2021), is the source of the quotation of 20 NYCRR 105.20 on presence for any part of a calendar day, the reference to Leach v Chu, 150 AD2d 842, and its affirmance by the Appellate Division, the "for whatever reason (business or pleasure)" language, the "stepping over the state line for one second" and "common sense must prevail" passage, the statement that presence for brief periods would normally constitute days, the Matter of John and Patricia D. Klingenstein (DTA No. 815156) facts and the Conclusion of Law H quotation on the absence of a shopping or dining exception, the statement that the 183-day rule and the permanent place of abode test are separate and distinct factors, the two travel branches of 20 NYCRR 105.20(c) and the JFK example, the two criteria of activity incidental to travel and degree of control and the cruise and stopover examples, the list of incidental travel-day activities including terminal purchases, ATM access, stopping for gas, and parking to meet a limousine, the Stranahan v State Tax Commission (68 AD2d 250, 416 NYS2d 836, 3d Dept 1979) medical holding and the audit policy on confinement to a medical institution, the Matter of Ralph and Leona Kern (240 AD2d 969) outpatient holding, the Matter of Dr. Charles F. Brush III and The Estate of Ellen S. Brush (DTA No. 817204) Conclusion of Law N quotation, the framing of the taxpayer burden as proving fewer than 184 days, and the weekend-days instruction to auditors: https://www.tax.ny.gov/pdf/2021/misc/nonresident-audit-guidelines-2021.pdf.

N.Y. Comp. Codes R. and Regs. tit. 20 section 105.20 is the source of the regulation text itself, including the day-counting rule in subdivision (c) and its exceptions for presence solely for the purpose of boarding a plane, ship, train or bus for travel to a destination outside New York State, or while traveling through New York State to a destination outside New York State: https://www.law.cornell.edu/regulations/new-york/20-NYCRR-105.20.

Minn. Stat. section 290.01, subdivision 7, is the source of the abode-plus-more-than-one-half-of-the-tax-year test, the armed forces and section 290.081 reciprocity carve-outs, the sentence that presence within the state for any part of a calendar day constitutes a day spent in the state, and the requirement that individuals keep adequate records to substantiate days spent outside the state: https://www.revisor.mn.gov/statutes/cite/290.01.

Minn. R. 8001.0300, subpart 4, is the source of the rule that a person shall be treated as present in Minnesota on any day if physically present at any time during that day, the in-transit exception for a person present less than 24 hours between two points outside Minnesota, the worked flight-change example arriving 7:00 P.M. on March 1 and departing 1:00 P.M. on March 2, and the record categories of calendars, diaries, canceled checks, credit card receipts, and airline tickets: https://www.revisor.mn.gov/rules/8001.0300/.

Minnesota Department of Revenue, "The 183-Day Rule," is the source of the department’s own statement of the two-part test, the phrasing that a taxpayer spends at least 183 days in Minnesota during the year with any part of a day counting as a full day, and the definition of an abode as a residence suitable for year-round use and equipped with its own cooking and bathing facilities: https://www.revenue.state.mn.us/183-day-rule.

Maryland Comptroller, Maryland Income Tax Administrative Release No. 37 (Domicile and Residency), is the source of the resident definition under Tax-General Article section 10-101(k) and COMAR 03.04.02.01B, the definition of a day as any part of a day with the proviso that a continuous period of 24 hours or less may not constitute more than one day, the statement that the two most important criteria in determining domicile are where the person lives and where the person is registered to vote, and the guidance that a vacation home or a home used to visit family and friends does not create statutory residency unless the 183-day presence threshold is independently met: https://www.marylandcomptroller.gov/content/dam/mdcomp/tax/legal-publications/administrative-releases/income-and-estate-tax/ar_it37.pdf.

Utah Admin. Code R865-9I-2, implementing Utah Code section 59-10-136, is the source of the definition of a day, for purposes of the 183-or-more-day test, as a day in which the individual spends more time in Utah than in any other state: https://www.law.cornell.edu/regulations/utah/Utah-Admin-Code-R865-9I-2. The superseded 1997 advisory opinion 97-016, which read the prior statute to count a fraction of a calendar day as a whole day, is at https://tax.utah.gov/commission/ruling/97-016.htm.

Ohio Rev. Code section 5747.24 is the source of the contact period definition, the definition of being away overnight from an abode located outside Ohio, and the presumption of non-Ohio domicile at no more than 212 contact periods: https://codes.ohio.gov/ohio-revised-code/section-5747.24.

Idaho Code section 63-3013 is the source of the 270-day aggregate threshold and the sentence providing that presence within the state for any part of a calendar day constitutes a day spent in the state unless the individual can show that the presence was for a temporary or transitory purpose: https://legislature.idaho.gov/statutesrules/idstat/title63/t63ch30/sect63-3013/.

Larson v. Commissioner of Revenue, 824 N.W.2d 329 (Minn. 2013), is the source of the Minnesota Supreme Court’s affirmance of a residency finding for tax years 2002 through 2006 against a taxpayer who claimed a 1998 move to Nevada: https://law.justia.com/cases/minnesota/supreme-court/2013/a11-1795.html.

Fla. Stat. section 196.161 is the source of the homestead exemption recapture reaching any year within the prior 10, the penalty of 50 percent of the unpaid taxes for each year, and the 15 percent interest per year: http://www.leg.state.fl.us/statutes/index.cfm?App_mode=Display_Statute&URL=0100-0199/0196/Sections/0196.161.html.

The count of how the 56 US jurisdictions treat partial days, the Minnesota exit-mistake list including landing at exactly 183 days, the Minnesota and Maryland audit-aggressiveness and exit-stickiness ratings, and the Florida homestead cross-check against driver license and voter registration data come from ResidencyIQ’s own dossier research, with underlying citations on the New York, Minnesota, Maryland, and Florida residency guides.