"Horse and buggy day" refers to a bygone era in history, when transportation was powered by horses and carriages instead of modern cars and buses. Synonyms for this phrase include "historic era", "olden days", "bygone times", and "days of yore". These terms evoke a sense of nostalgia for a simpler time, when life moved at a slower pace and people relied on more traditional means of travel. They can also be used in a figurative sense to describe situations or practices that are outdated or no longer relevant in modern times. Overall, these synonyms capture the charm and historical significance of the days when horses and buggies were the norm.