Data sources & licences

Every number on a sheet has a source. This page names each one, its licence, and the attribution it carries.

Astronomy — computed in-house

Sunrise, sunset, solar noon, twilight, moonrise, moonset, moon phases, equinoxes and solstices are computed by our own engine from standard solar and lunar geometry. No external service or dataset is involved, so there is nothing to credit.

Licensed and credited sources

Time zone boundaries (timezone-boundary-builder 2026c)

Licence: ODbL 1.0 (licence text)

Time zone suggestions use boundary data © OpenStreetMap contributors, ODbL 1.0, via timezone-boundary-builder 2026c. The time zone printed on a sheet is the one its buyer selected from the public-domain IANA time zone database.

Source

⚠ COUNSEL: review of the ODbL produced-work severance argument (user-confirmed selection off public-domain tzdata), and whether compiling the boundary data into the binary constitutes conveying the database. Both are owed before the first paid sheet.

LocationIQ

Licence: Vendor terms of service (licence text)

Geocoding and map tiles by LocationIQ. Location data © OpenStreetMap contributors, ODbL 1.0.

Source

NOAA CO-OPS tide predictions

Licence: Public domain (US Government)

Tide times are synthesised from harmonic constituents published by NOAA's Center for Operational Oceanographic Products and Services, for the station nearest the sheet's coordinates. Tide columns are offered where a station is near enough to stand for the place, and withheld where none is.

Source

Type

EB Garamond

Licence: SIL Open Font License 1.1

Display and text face on the sheets. Instanced to static weights; the family declares no Reserved Font Name, which is what makes instancing lawful under OFL §3.

Project page

IBM Plex Sans Condensed

Licence: SIL Open Font License 1.1 (Reserved Font Name “Plex”)

Data columns. Used byte for byte as published — the reserved name forbids modified versions, so these files are never instanced.

Project page

IBM Plex Mono

Licence: SIL Open Font License 1.1 (Reserved Font Name “Plex”)

Tabular figures. Used byte for byte as published, never instanced.

Project page

Shippori Mincho

Licence: SIL Open Font License 1.1

CJK fallback. Japanese and traditional-Chinese characters in a customer's title, place name or dedication are set in this face, which the sheets' Latin faces have no glyphs for. Used byte for byte as published, never instanced.

Project page

Noto Serif KR

Licence: SIL Open Font License 1.1

CJK fallback, Korean. Hangul in a customer's title, place name or dedication is set in this face. Instanced to a static weight; the family declares no Reserved Font Name, which is what makes instancing lawful under OFL §3.

Project page

Registered, not yet shipping

These sources are registered for tide coverage outside the United States and for climate columns. None of their data appears on any sheet or page yet; their attributions will appear here — and, where required, on the sheets that use them — when they ship.

TICON-4 tidal constants

About 4,200 tide gauges worldwide · Licence: CC BY 4.0

Not yet shipping. Will power tide columns outside the US; its attribution will appear on sheets that use it.

FES2022 ocean tide atlas

Global ocean grid · Licence: Free from AVISO, citation required

Not yet shipping. Produced by LEGOS, NOVELTIS and CLS, funded by CNES, distributed by AVISO; commercial terms under verification.

GHCN-Daily

More than 100,000 weather stations in 180 countries · Licence: CC0 1.0 via NOAA NODD

Not yet shipping. Will power climate-normal columns.

NCEI 1991–2020 US Climate Normals

United States, 15,000+ stations · Licence: Public domain (US Government)

Not yet shipping. Will power US climate-normal columns.