A public-holiday calendar records the days United States has set aside as statutory time off. National holidays apply nationwide; where an official regional or provincial list is published, those dates are included separately and clearly labelled rather than folded into the national figures. This calendar is a reference, not a legal determination of anyone's leave entitlement. Dates move for two common reasons: many countries observe a fixed-date holiday on the nearest working day when it falls at a weekend, and some observances follow lunar or other non-Gregorian reckoning that shifts against the everyday calendar. Regional holidays are always shown as regional and never added to the national count. The licence terms and the government producer behind each list are credited on the sources page.
Reading the table
The table gives the date a holiday falls on, the observance date when a weekend shift or substitute day applies, and notes published with the source. A Regional · <region> badge marks a holiday that applies only in that region; it is never counted as nationwide. Some countries publish both the original date and the observed date, so both are shown instead of silently adjusting one. Employers, schools, and individual workplaces may follow different calendars or grant extra days, so treat this table as a guide rather than an entitlement. For a wider comparison of why observance moves between countries, see why holiday dates differ between countries. For the American case specifically, see the US federal holidays guide. The official source is always the final authority.
Where these dates come from
The United States desk follows the federal holiday list published by the Office of Personnel Management under 5 U.S.C. § 6103, the same dates observed by executive-branch agencies. OPM material is a work of the U.S. federal government and is reused here as public domain. The list is national only: state public holidays are not included, because no single official state calendar released under a reusable commercial licence was identified. Fixed-date holidays follow the federal weekend rule, so a holiday that falls on Saturday is observed on the preceding Friday and one that falls on Sunday moves to the following Monday; the table shows the observed date and notes the actual one. OPM publishes a fresh schedule each year, so the desk is refreshed from that source rather than edited by hand. Because the federal list is set by statute, it changes only when Congress acts, so most years repeat the same eleven dates. The weekend shift is a federal rule rather than a state one, though some states follow their own schedules for their own employees.