Sources & licenses

Holiday data

Nager.Date provides the 40-country holiday snapshots. Its upstream project is MIT licensed; the upstream license and per-file provenance are included with this site. Snapshots cover 2020–2030, with adjacent-year support for calendar packs. Retrieved October 2, 2026. National scope is checked when a calendar is generated.

US federal dates

The US Office of Personnel Management publishes federal holiday schedules and weekend observance rules. These government facts are used for the US calendar. See the source links below for the official schedules.

Fonts & PDF library

Geist and Geist Mono are licensed under the SIL Open Font License 1.1. Printable text uses Noto Sans under the same license. License files are vendored alongside the fonts. FPDF 1.86 is distributed under its permissive upstream license, included in the source.

Measurements

A4 and A5 use ISO 216 dimensions. US Letter and Legal use standard inch dimensions, converted at exactly 25.4 millimeters per inch. ISO 8601 week numbering follows the Monday and January 4 rule.

Read the original sources

• Nager.Date: holiday data and MIT license
• OPM: US federal holiday schedules
• ISO 8601: dates and week numbering
• ISO 216: A-series paper sizes
• Geist & Geist Mono
• Noto fonts
• FPDF