Chinese calendar dating
Other calendars have one (or multiple) larger units of time.
Calendars that contain one level of cycles: Very commonly a calendar includes more than one type of cycle, or has both cyclic and non-cyclic elements. For example, the vast majority of them track years, months, weeks and days. A day may consist of the period between sunrise and sunset, with a following period of night, or it may be a period between successive events such as two sunsets. A lunar calendar is one in which days are numbered within each lunar phase cycle.
The most common type of pre-modern calendar was the lunisolar calendar, a lunar calendar that occasionally adds one intercalary month to remain synchronised with the solar year over the long term.
Thus the week cycle is by itself not a full calendar system; neither is a system to name the days within a year without a system for identifying the years.
The Roman calendar was reformed by Julius Caesar in 45 BC.
The Julian calendar was no longer dependent on the observation of the new moon but simply followed an algorithm of introducing a leap day every four years.
Amongst such calendar systems was the calendar system of the Persian Empire, which in turn gave rise to the Zoroastrian calendar as well as the Hebrew calendar.
A great number of Hellenic calendars developed in Classical Greece, and with the Hellenistic period also influenced calendars outside of the immediate sphere of Greek influence, giving rise to the various Hindu calendars as well as to the ancient Roman calendar.