Travel Days Counter

If you split your time between countries, sooner or later you have to answer a deceptively simple question: how many days have I actually spent here? That number sits behind a tax-residency test, a visa condition, or the US IRS Substantial Presence Test — and it is easy to get wrong when trips overlap, get rebooked, or straddle a year boundary.

This counter takes up to eight entry/exit date ranges, deduplicates any overlapping or touching days so a calendar day is only ever counted once, and reports the total under the counting convention you choose. It then checks that total against a threshold (183 by default) over two independent windows — the current calendar year and a rolling 365-day window — and can optionally run the IRS Substantial Presence Test weighting.

Real statutory tests genuinely disagree on what counts as “a day”, so the tool exposes a toggle rather than silently picking one:

• Inclusive (“any part of a day”) — used by the IRS and the OECD Model Tax Convention. If you were present for any part of a day it counts, so both the arrival day and the departure day count: per trip (exit − entry) + 1.
• Nights (midnight rule) — the UK Statutory Residence Test default. A day counts only if you were still in the country at the end of the day, so the arrival day counts but the departure day usually does not: per trip (exit − entry), i.e. the number of nights.

The 183-day line is only meaningful measured inside a bounded ~12-month period, so the counter never reduces it to one ambiguous flag driven by the raw total. Instead it reports a threshold status and a days-remaining figure for each window separately:

• Calendar year — days falling in the same 1 January – 31 December year as your “as of” date. Future-dated days within that year still count, so you can project a plan.
• Rolling 365 days — a fixed 365-date window ending on your “as of” date; it can span two calendar years and never includes days after “now”.

The two windows can legitimately disagree near a year boundary, which is exactly why they are shown side by side. If you specifically need the EU short-stay rule, use the dedicated Schengen 90/180-day calculator instead — that tracks 90 days in any rolling 180-day period, a different rule from the 183-day line here. If your concern is passport validity rather than presence, the passport six-month rule checker answers that question.

For each entered trip with entry date E and exit date X, the tool builds the set of calendar days you were present, takes the union across every trip (deduplicating overlaps and touching ranges), and filters that set by each window:

daysInclusive = (X − E) + 1      # any part of a day
daysNights    = (X − E)          # midnight rule

D = union of every present day across all trips   # overlaps counted once
totalDays       = |D|
currentYearDays = days in D whose year == year(asOfDate)
rolling365Days  = days in D within [asOfDate − 364 .. asOfDate]

thresholdMet(window)   = windowDays >= T          # T = 183 by default
daysRemaining(window)  = max(0, T − windowDays)

The >= boundary is inclusive: exactly 183 days meets the threshold with 0 remaining. Day differences use UTC calendar arithmetic, so a leap day inside a range is counted correctly (28 Feb → 1 Mar is 3 days in 2024 but 2 days in a non-leap year).

Three separate 2026 trips, counted with the inclusive convention as of 31 December 2026 (so both windows coincide). Generated by the same engine that powers the calculator above.

The three trips are 16 + 16 + 108 = 140 days and do not overlap, so the total is 140. That is below 183, leaving 43 days before the threshold would be met in either window.

Turning on SPT mode reuses the trips you already entered, buckets them by calendar year, and applies the IRS weighting: current-year days, plus one-third of the first preceding year, plus one-sixth of the second preceding year. You meet the test when the weighted total reaches 183 and you were present at least 31 days in the current year.

The 183-day line appears across several regimes, but the day convention and the measurement window differ. This is a reference summary, not a determination for any specific case:

This is an informational day counter, not tax, immigration or legal advice. It counts raw physical-presence days only and deliberately does not model statutory exclusions:

• IRS carve-outs for exempt individuals, cross-border commuters, medical conditions that prevented you leaving, and transit days (Form 8843) are not applied.
• The UK SRT deeming rule and its capped “exceptional circumstances” exclusion are not applied.
• Overlap dedupe assumes every entered range is presence in a single jurisdiction — do not mix trips to different countries into one total.
• Actual residency depends on treaty tie-breakers, domicile and sufficient-ties tests this tool does not model. Only a qualified tax professional or the relevant tax/immigration authority can give an authoritative answer.

If you are just measuring an interval between two dates for a non-tax reason, the age difference calculator gives a plain years/months/days breakdown instead.