I vaguely remembered a short story where a person at a cocktail party had been a different gender the week before, although some people never changed. It might

I vaguely remembered a short story where a person at a cocktail party had been a different gender the week before, although some people never changed. It might be: > Robert Silverberg's Son of Man (1971), whose protagonist is transposed into the Far Future and there experiences a wide range of ways of being human, including being female... See https://sf-encyclopedia.com/entry/transgender_sf https://sf-encyclopedia.com/entry/transgender_sf for many entries before 1990, or even 1900.