when did we start using the days of the week
Week The seven-day week seems to have been adopted, at different stages, by the Persian Empire, in Hellenistic astrology, and (via Greek transmission) in Gupta India and Tang China.[b][citation needed]
Children's Day Children's Day observations in the United States predate both Mother's and Father's Day, though a permanent annual single Children's Day observation is not made at the national level.
Colon (punctuation) Syntactical-descriptive colons may separate the numbers indicating hours, minutes, and seconds in abbreviated measures of time.[5]
Day In common usage, it is either an interval equal to 24 hours[4] or daytime, the consecutive period of time during which the Sun is above the horizon. The word day may also refer to a day of the week or to a calendar date, as in answer to the question, "On which day?" The life patterns (circadian rhythms) of humans and many other species are related to Earth's solar day and the day-night cycle.
Economic nationalism While the coining of the term "
Horse and buggy By the early 1910s, the number of automobiles had surpassed the number of buggies, but their use continued well into the 1920s in out of the way places.