Terms of use

Every figure here is computed from published algorithms and public reference data, and the sun and moon times are checked against US Naval Observatory values — the method and the measured error are set out on the about page. The site is built to be right and it is tested to be right.

It is still provided as is, with no warranty that it is accurate, complete or available. Three limits are worth knowing:

• Sunrise and sunset are computed for a flat horizon at sea level. Terrain, altitude and unusual refraction will move the real time, and the error grows above 60° of latitude.
• Islamic dates follow the Umm al-Qura convention. Observance set by local sighting can differ by a day, and where that matters you should follow your own community.
• Time zone rules change by legislation, sometimes at short notice. Dates far in the future reflect the rules as they stand today.

Do not rely on this site alone for anything with legal, financial, medical, safety or religious consequence. Check an authoritative source.

The underlying facts — dates, times, offsets — are not anyone’s property and you are welcome to use them. The wording, design and code of the site are not; please do not republish pages wholesale or scrape the site at volume.

Much of the source data is public domain and free for you to use directly: the IANA time zone database, US Census Bureau files, and US Naval Observatory and NOAA publications.

To the extent the law allows, no liability is accepted for loss arising from relying on this site — a missed appointment, a mistimed booking, a decision made on a date shown here. The site is free, it is provided as is, and the section above says plainly where its limits are.

Nothing here limits liability for death or personal injury caused by negligence, for fraud, or for anything else that cannot lawfully be excluded.

These terms, and any dispute arising from them or from use of this site, are governed by the laws of England and Wales, and the courts of England and Wales have jurisdiction.

If you are a consumer, this does not take away the protection of any mandatory law of the country you live in, or your right to bring proceedings there.

These terms may change; the date at the top says when they last did. Questions, or a figure that looks wrong, to contact@datealmanac.com.