Terms of Use
World Time Lab is free to use and asks nothing of you. In return, these are the limits of what it promises: it publishes calculations for general information, not authoritative times for decisions that carry risk.
Last reviewed July 21, 2026Site version v2026.7.5
Using the site means accepting these terms
By reading World Time Lab or using any tool on it, you accept the terms on this page. If you do not accept them, please do not use the site. There is nothing to sign and no account to create, so use is the only signal of acceptance either side has.
These terms are published by the operator of World Time Lab, and cover the site at worldtimelab.com and every page under it.
What World Time Lab provides
World Time Lab provides computed reference information: local times and time zone offsets, sun and moon positions and times, seasonal and eclipse data, calendars and date arithmetic, distances, and an educational planet simulator. Results are produced by published algorithms and public datasets, described in detail on the methodology page.
It is a reference, not a service. There is no uptime commitment, no support contract, and no guarantee that any page, tool, or URL will continue to exist.
No warranty, especially for time-critical use
Everything here is provided as is and as available, without warranties of any kind, whether express or implied, including any implied warranty of accuracy, fitness for a particular purpose, or non-infringement. Times are displayed to the minute and carry the uncertainties documented on the methodology page.
Do not rely on World Time Lab where being wrong has consequences. That includes, without limitation:
- Navigation, aviation, and maritime operations, including flight planning, celestial navigation, night-flying currency, and tide or twilight limits. Use the official almanac and the authorities for your operation.
- Safety of life and emergency planning, including search timing, expedition turnaround times, and any decision that depends on the light lasting.
- Legal and contractual deadlines, including filing cut-offs, statutory time limits, auction and tender closes, and anything measured against a court's or registry's official clock.
- Religious observance, including prayer times, fasting start and end times, sabbath boundaries, and any date fixed by moon sighting or by a religious authority. Follow your own community's ruling, which World Time Lab cannot represent.
- Surveying, engineering, scientific measurement, and legal astronomy, where a minute of error or a sea-level horizon assumption is not acceptable.
- Medical, financial, and other professional decisions. World Time Lab gives calculations, never advice.
Sun and moon times assume a flat horizon at sea level with standard refraction. Terrain, buildings, altitude, and unusual atmospheric conditions all move the real event, sometimes by many minutes. Time zone rules come from the database inside your own browser, so a device that has not been updated can show an outdated offset for a country that recently changed its clocks.
Acceptable use
You are welcome to:
- Use the tools as much as you like, for personal, educational, or commercial work.
- Link to any page, including deep links to a specific city, date, or calculator.
- Quote a result with a link back, or cite the methodology page as your source.
- Print or export what a page offers to print or export.
Please do not:
- Crawl or automate the site so aggressively that it degrades service for other readers, or ignore the directives in robots.txt.
- Republish substantial parts of the site's pages or datasets as your own work, or present World Time Lab's output as authoritative for the uses excluded above.
- Attempt to interfere with the site, its host, or other readers, or to bypass technical limits.
- Imply endorsement, partnership, or affiliation with World Time Lab or with any organization whose public data it uses.
- Use the site in a way that breaks the law where you are, or that infringes the license of an underlying dataset.
Intellectual property
The site's own text, page design, interface, illustrations, and source code are the work of the operator of World Time Lab and are protected by copyright. Nothing on this page grants a license to copy them wholesale.
Underlying data is a different matter and is notWorld Time Lab's to license. Map geometry, time zone boundaries, administrative regions, city coordinates, climate classifications, holiday tables, and astronomical catalogs all come from third-party sources, each under its own terms: public domain, Creative Commons Attribution 4.0, the Open Database License, and permissive software licenses among them. Those obligations, including attribution and share-alike where required, travel with the data.
The methodology page names every source with its terms and its currency. If you intend to reuse a dataset, go to that source and comply with its terms directly rather than relying on this site.
Trademarks, place names, and organization names mentioned on the site belong to their respective owners and are used descriptively.
Third-party links and services
World Time Lab links to external sources so you can check its work. Those sites are not under its control, and a link is neither an endorsement nor a warranty about the linked content. Where a build includes advertising or analytics, those services operate under their own terms and privacy policies, described in the privacy policy and the cookie policy.
Changes to the site and to these terms
The operator of World Time Lab may change, add, or remove any part of World Time Lab at any time, including pages, tools, data sources, and URLs, and may stop publishing the site altogether. Data is regenerated from upstream sources periodically, so values shown today can differ from values shown later even for the same date.
These terms can change too. The reviewed date at the top of this page and the site version identify the text you are reading; continuing to use the site after a change means accepting the current version. Material changes are worth re-reading rather than assuming.
Liability
To the fullest extent permitted by the law that applies to you, the operator of World Time Lab is not liable for loss or damage arising from use of, or reliance on, this site, including loss of profit, missed deadlines, travel disruption, or any indirect or consequential loss.
Some jurisdictions do not allow certain exclusions of warranty or liability. Where that is the case, the exclusions above apply only to the extent permitted, and nothing here limits any right you have under mandatory consumer law or excludes liability for fraud or for death or personal injury caused by negligence.
These terms do not name a governing jurisdiction. World Time Lab does not publish a legal entity or registered address, so it would be dishonest to nominate a forum or a governing law here. Nothing in this document waives rights you hold under the mandatory law of your own country.
Questions
Questions about these terms, about reuse, or about a specific license go through the contact page. If something on the site is factually wrong, the corrections page is the faster route.
Terms, licensing, and reuse questions.