Editorial standards

How we get this right.

Our guides cover decisions where one day can change a tax bill or a visa outcome. Here's who stands behind them, what they're checked against, and how we keep them current.

Who's behind Chrono

A real company, building this in software.

Chrono is built by Bloodhound Intelligence, Inc., a company building infrastructure for verified, user-controlled records of presence. Chrono is our consumer application: it tracks where you live, work, and travel so that residency rules, visa limits, and exposure thresholds have a reliable answer.

That's why these guides exist. The questions they answer — how the 90/180 rule actually counts, when a second home triggers statutory residency, what a record needs to look like to hold up later — are the same questions we engineer the product around. The writing is editorial; the understanding behind it is operational.

How we research

Checked against the source that makes the rule.

Primary sources first

We cite the authority, not a summary of it.

Every guide is checked against the body that actually makes the rule — the IRS, state tax departments, EU and member-state immigration authorities, and the statutes themselves. Those links are listed in each guide's Sources, so you can verify the claim at its origin.

Built from the problem

Experience, not aggregation.

Chrono is a presence-tracking product. These guides come from the same work as the app — counting days correctly under the 90/180 rule, separating domicile from statutory residency, building a record that survives an audit. We write what we've had to get right in software.

Plain, current, specific

Accurate beats clever.

We name the threshold, the jurisdiction, and the date a rule takes effect. Where the law is unsettled or varies by state, we say so rather than flatten it into a single tidy number.

Keeping it current

Dated, and revisited when the rules move.

Every guide shows a Last reviewed date at the top. That date is the last time we re-checked the guide against its primary sources — not just the last time we touched the file.

Residency thresholds, fees, and immigration timelines change. ETIAS dates have already shifted more than once; states adjust day-count rules. When a source we rely on changes, we update the affected guides and move the review date forward. If you find something that's fallen out of date, tell us.

The boundary

Information you can act on — not personalized advice.

These guides, and the estimates our tools produce, are general information about how the rules work. They are not legal, tax, or immigration advice, and they don't account for the specifics of your situation. For a decision with real consequences, confirm it with a qualified professional who can review your facts.

Found an error, or a source that's changed? We want to know. Send us a correction →