Analysis of information sources in references of the Wikipedia article "일정" in Korean language version.
This obsession with timekeeping isn't anything new, though. Ancient schedules revolved around annual, seasonal, monthly, or daily rhythms, and innumerable examples of timekeeping structures and rock carvings from these early cultures still pepper our planet in famous places like Stonehenge in Wiltshire County, England, and in less famous places like the V-V Ranch Petroglyph site near Sedona, Arizona.
The hunters[' ...] schedule is uneven. it is not unusual for a man to hunt avidly for a week and then do no hunting at all for two or three weeks. Since hunting is an unpredictable business and subject to magical control, hunters sometimes experience a run of bad luck and stop hunting for a month or longer. During these periods, visiting, entertaining, and especially dancing are the primary activities of men.