Official public, bank and statutory holidays for 13 countries and 46 regions, each checked against the government's own list.
Every list is compared, date by date, with the official list published by the government (for example GOV.UK, the U.S. Office of Personnel Management, Fair Work Australia and each Canadian province). Holidays that can only be fixed close to the day, such as Eid in some countries, are marked as expected until they are declared. We re-check the official sources every month.