The Mayan Calendar Round is composed of both the Haab and the Tzolk'in calendars. The Tzolk'in is the inner red circle, while the Haab loops around. To structure the Calendar Round date, 4 dates are needed: the Tzolk'in day number, the Tzolk'in day name, the Haab day number, and the Haab month symbol, in that order. The Tzolk'in date is recorded first and then the Haab date, such as 1 Kan 1 Pop. Each 260-day Tzolk'in cycle brings a completely new set of dates, until the exact dates of the Tzolk'in and the Haab co-occur after 52 years.
This system does not have a particular time of creation and only exists through its 52-year cycles. Therefore, the Calendar Round isn’t reliable for dating historical events beyond 52 years.
The circular shape of the Calendar Round depicts time perfectly in the sense that time is infinite, with no visible beginning nor end. It also accurately portrays the cyclical nature of this calendar.
Above is an image of the Calendar Round in the form of interlocking gears. As the Haab wheel (the largest gear) rotates, a Tzolk'in date locks into place and aligns with a Haab date. Within the Tzolk'in wheel are the 13 numbers that cycle within the 20 days of the Tzolk'in.