# Endless River — Countly > Countly is a private, automatic day-counter for people who live across borders. It counts the days you spend in each country — only on your phone — and watches the thresholds that matter: tax residency, the Schengen 90/180 rule, visa limits, and US-state & Canadian-province residency days. Endless River is the small software studio that makes it. Countly's own site, https://countlyapp.com, hosts a free public day calculator, plain-language explainers of the rules, and the Countly Journal; the links below are its canonical URLs. The free tools below run the exact day-counting engine inside the Countly app, so the numbers match to the day. All counting happens in the browser — nothing is uploaded. Everything here is informational, not legal or tax advice; border and tax rules have exceptions and should be verified with the relevant authorities. ## Free tools - [Day calculator](https://countlyapp.com/calculator): Calculate the Schengen 90/180 rule, 183-day tax residency, the UK Statutory Residence Test, and US-state & Canada day limits. Add your trips; see days used, days left, your latest safe date, and the rolling 180-day window. Free, private, no sign-up. - [Embeddable calculator](https://countlyapp.com/calculator/embed): The same calculator as a chromeless iframe other sites can embed. - [Rules dataset (JSON)](https://countlyapp.com/rules.json): Machine-readable summary of every rule — thresholds, reference periods, and authoritative sources. CORS-open for AI/agent use. ## The rules, explained - [Schengen 90/180 rule](https://countlyapp.com/rules/schengen-90-180): How the rolling 180-day window works, why entry and exit days both count, and how the 90 days are shared across the Schengen Area. - [The 183-day tax-residency rule](https://countlyapp.com/rules/183-day-tax-residency): What the 183-day threshold means, how reference periods differ by country, and why it is rarely the whole test. - [UK Statutory Residence Test](https://countlyapp.com/rules/uk-statutory-residence-test): How UK day counts work across the 6 April–5 April tax year. - [US statutory residency (NY, NJ, CT, MA, PA)](https://countlyapp.com/rules/us-statutory-residency): The "more than 183 days" statutory-residency test used by several US states. - [New York 183-day rule (incl. NYC)](https://countlyapp.com/rules/new-york-183-day-rule): How New York State and New York City count residency days. - [California residency presumption](https://countlyapp.com/rules/california-residency-presumption): Why California uses a nine-month (~274-day) presumption instead of a bright-line day rule. - [Canada 183-day rule](https://countlyapp.com/rules/canada-183-day-rule): The federal deemed-residence day count and how ties can change it. ## Questions answered - [Countly answers](https://countlyapp.com/answers): Short, sourced answers to common day-counting questions (transit days, overstays, dual residency, how a day is counted, and more). ## Passport Power — passports & residence permits, rated in days - [Passport Power board](https://countlyapp.com/passports): The Countly Passport Score for 199 passports — a passport index that also counts how long each door stays open (allowed stay, days-weighted) and what each destination is worth, not just how many borders open. The formula is published and recomputable; corroboration, retained provenance and rows needing verification are labelled separately. - [Residence-permit power](https://countlyapp.com/residency): 70 countries scored on what a residence permit unlocks, the physical-presence days it costs to keep, and the path to permanent residency and citizenship. Temporary (ВНЖ) and permanent (ПМЖ) boards. The presence-days column no other index publishes. - [Methodology](https://countlyapp.com/passports/methodology): Exact formulas, factor tables, the two-source + official-adjudication verification pipeline, and honest caveats. - [Passport Power dataset (JSON)](https://countlyapp.com/passports.json): Machine-readable passport scores, sub-indices, entry-class counts and residence scores. CORS-open for AI/agent use. - Localized in 6 languages via path prefixes on countlyapp.com: `/de/passports`, `/es/passports`, `/fr/passports`, `/pt/passports`, `/ru/passports` (and the same for `/residency`), with hreflang alternates. Individual passport pages live at `https://countlyapp.com/passports/{country}` (e.g. `https://countlyapp.com/passports/germany`) and residence pages at `https://countlyapp.com/residency/{country}`. ## The Countly app - [Countly](https://countlyapp.com/): The automatic, private day-counter for iPhone and Android. Tracks countries, Schengen, tax residency, and US-state / Canadian-province days; works offline; no account. - [Countly Journal](https://countlyapp.com/journal): Careful writing on tax residency, the Schengen rule, visas, and life across borders. - [Countly editorial policy](https://countlyapp.com/editorial-policy): Authorship, source standards, corrections, translation policy, and the site-wide informational disclaimer. ## Little Firsts — bilingual storybooks for ages 4–6 - [Little Firsts](https://www.endlessriver.xyz/little-firsts): A gentle storybook app that grows a child's first words in two languages at once. Illustrated stories read in either language with a tap, narrated aloud, with tappable words and a growing First Words picture dictionary. Six languages (English, Russian, Spanish, French, German, Mandarin Chinese). 100% offline, no account, no ads, no tracking. Free to try; one subscription unlocks every story. iPhone & Android. - [Little Firsts Journal](https://www.endlessriver.xyz/little-firsts/blog): Warm, practical writing for parents raising bilingual children — first words, reading aloud together, bedtime, and per-language guides. Published in all six languages with hreflang-linked translations. - [Little Firsts editorial policy](https://www.endlessriver.xyz/little-firsts/editorial-policy): Team authorship, evidence standards, developmental-safety boundaries, corrections, and translation policy. - [Privacy](https://www.endlessriver.xyz/little-firsts/privacy) · [Terms of use](https://www.endlessriver.xyz/little-firsts/terms) · [Support](https://www.endlessriver.xyz/little-firsts/support) ## Studio - [Endless River](https://www.endlessriver.xyz/): A small studio of quiet software. - [Privacy](https://countlyapp.com/privacy) - [Terms of use](https://countlyapp.com/terms)