<Ul> <Li> week and weekday--this system (without year, the week number keeps on increasing) is not very common </Li> <Li> year and ordinal date within the year, e.g., the ISO 8601 ordinal date system </Li> </Ul> <Li> week and weekday--this system (without year, the week number keeps on increasing) is not very common </Li> <Li> year and ordinal date within the year, e.g., the ISO 8601 ordinal date system </Li> <P> Calendars with two levels of cycles: </P>

8. where did the western society’s calendar come from