Two things in the atlas are tied to this date. Each is placed here by a source that gives the day.
A 1957 accident at the Mayak nuclear facility in the Southern Urals that spread radioactive fallout and led to mass evacuations. It was kept secret, and the regional press guessed that the glow seen in the sky on 29 September was the northern lights.
A 1999 painting by the artist Yuko Tatsushima that internet creepypasta paired with the poem Tomino's Hell and called cursed.