A clock (from the Latin cloca, "bell") is an instrument for measuring time. True clocks have an announcing or striking mechanism that sounds after each set interval of time, usually by ringing a bell (which, as previously indicated, originally gave the clock its name), chimes, or gong. A silent clock without a striking mechanism is traditionally known as a timepiece, a term sometimes used by horologists and other specialists to describe ordinary wrist watches and other timekeeping devices lacking a striking mechanism (see Baillie et al., p. 307; Palmer, p. 19; Zea & Cheney, p. 172)."Clock" is derived from the French, cloche, which in turn was derived from the Latin term, cloca. In French, cloche is feminine, so when referring to the hour "by the bell" it takes the a la and puts it into the masculine form au cloche, properly pronounced with a long õ then "Clõsh." So, au cloche in French becomes in English o'clock, which however in older English usage was sometimes spelled "of the clock". The advent of the clock tower and bell approximates the Norman influence in England. While the Normans were of Scandinavian descent, they spoke French.The clock is one of the oldest human inventions, to quantify and label the physical process known as change. As the seasons and the phases of the moon can be used to measure the passage of longer periods of change, shorter processes of measurement were desired, hence the invention of the terms, "hours" and "minutes".A calendar is a system for naming periods of time, typically days. These names are known as calendar dates. Cycles in a calendar are often synchronised with the perceived motion of astronomical objects.A calendar is also a physical device (often paper). This is the most common usage of the word. Other similar types of calendars can include computerised systems, which can be set to remind the user of upcoming events and appointments.As a subset, 'calendar' is also used to denote a list of particular set of planned events (for example, court calendar).As to who invented the clock & the calendar, well, you'd have to research on Ancient History. I believe you'd have to look for Ancient Egyptian, Greek, Roman, Norse, & Chinese to better understand these topics. No single person is responsible for the origins of the clock & the calendar. Although later developments indicate that the Gregorian Calendar, which we're using today, was created by Pope Gregory XIII. He's been accreditted for fixing the calendar.
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