An individual publishes World Date and Time at worlddateandtime.com. The World Date and Time editorial team writes the guides. There are no guest posts, no sponsored or partner content, and no paid links.
Guide drafts are written with the help of AI tools. Every time, offset and sunrise/sunset figure is computed from the site's data, including the IANA time zone database; every other fact is checked against a cited primary source before publishing. AI is not used to make images. Charts and tables are computed from data.
Clock changes and offsets come from the IANA time zone database. The site is built with time zone data no older than release 2026c, and the build stops if the data is older. Sun and moon figures use SunCalc and the astronomy-engine library for the city's coordinates. Public holidays come from the date-holidays dataset, with official government lists in its place where we have checked them. The methodology page names those lists. Each table on a guide carries a one-line note of how it was computed.
New guides cite at least three primary sources, such as legislation, a national metrology institute, or the IANA time zone database. Older notes are being brought up to that standard. Sources on a new guide are checked on the date it is published. News articles and forums are not used as factual sources. Each guide shows a Published date. The Updated date is the same until the content changes in a material way.
If a guide is wrong, write to [email protected] with the page and what is wrong. The correction goes into the page, and the Updated date changes.