Can calendars be reused? How many years have you been repeating it?

The Gregorian calendar is only repeated for 28 years, because 4 years is a leap year and a week (week) is 7 days. Their common multiple is 28, so it will remain the same after 28 years. You can look at the calendar in 2042, just like today. But if you count the lunar calendar, there is no rule. For example, this year is leap September, and the years of the following leap September are 2 109, 2204, 2223 and 2576. It is irregular, so it is impossible to repeat it if you count the lunar calendar, otherwise it will take tens of thousands of years to repeat it.

A calendar is a daily newspaper that records time. The first calendar in China was about 4000 years ago. According to a page of Oracle bone calendar in Oracle Bone Inscriptions, it is proved that the calendar of Yin Dynasty has reached a considerable level. This page of Oracle Bone Inscriptions is the oldest almanac of all mankind, and this page of Oracle Bone Inscriptions is also called the calendar. But the real calendar appeared. About 1 100 years ago, during the Yongzhenyuan period in Tang Shunzong, the imperial calendar was already used in the palace. Each page displays a calendar for one day, a monthly calendar for one month and an annual calendar for the whole year. Other time elements (units) included in the calendar are solar terms, centuries and years. Calendars come in many forms, such as wall calendars, desk calendars and calendar cards. And then the electronic calendar was developed. Calendars are often decorated with images, and monthly cards are one of the decorative paintings of calendars.