Wall calendars with julian dating
A calendar is also a physical record (often paper) of such a system.
Similarly, Michael Rappenglueck believes that marks on a 15,000-year-old cave painting represent a lunar calendar.
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.
This created a dissociation of the calendar month from the lunation.
A large number of calendar systems which were based on the Babylonian calendar, and which were found in the Ancient Near East, date from the Iron Age.
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.