On one 1883 day, parts of America experienced noon twice

Before railroads coordinated it, every town kept its own local solar time, which made scheduling trains chaotic. On 18 November 1883, US and Canadian railroads switched to standard time zones at a telegraphed signal, so some towns' clocks hit noon, then were reset back to hit noon again under the new zone.

— Wikipedia, Standard time — 18 November 1883