Every fact, sourced.

Number-one and top-five songs come from the official national charts of the country you choose during onboarding, licensed directly from the chart authority. Thirty-second previews come from Apple Music and Spotify under their respective developer agreements.

Headlines are sourced from licensed national newspaper archives and the wire-service archives of Reuters, the Associated Press, and Agence France-Presse. We pick one headline a day on the free Postcard tier and three on Magazine.

Local weather for your city on each day comes from national meteorological office archives, supplemented by NOAA and ECMWF historical data sets. Coverage starts in 1950 for most major cities.

Cinema listings come from licensed national film archives. TV schedules come from licensed broadcaster archives. Where a country's archive is incomplete, we mark the day clearly rather than guess.

Prices for bread, petrol, a cinema ticket, and similar everyday goods come from national statistical offices and central bank historical price series.

The short paragraph at the bottom of each Magazine and Chapter card is written by our editorial team, drawing on the sources above and on a curated bibliography of cultural histories. It is never about you personally, and never generated end-to-end by AI. AI tools assist with research and first drafts; an editor signs each paragraph off.

We make mistakes. If you spot one, write to corrections@yesterly-app.com with the date, the country, and the field that looks wrong. We correct the record and credit you, by initials, in the next monthly notes.