20 14 do I still need to buy a new calendar? Dig out the old calendar of 1986 to make do with it. Just after New Year's Day, some netizens found that this year's calendar was exactly the same as 1986, as if time had gone back. The original online 1986 calendar is also on sale at a high price. Local astronomical experts explained that it is not uncommon to have exactly the same date on the calendar last week. Usually it will be repeated once every 28 years.

Gao Buxi, executive vice president of Hubei Astronomical Society, said that the calendar consistency mentioned by netizens is actually that the date and week of the solar calendar in different years are the same. If a year is 365 days, that is, 52 weeks 1 day, then generally speaking, the number of weeks on a certain day in a year will be one week more than that on the same day in the previous year. However, considering leap years, the change is more complicated. Generally, 28 years is a complete cycle of change, but if this cycle spans a hundred years, it will be different.

To put it simply, only when we know the number of weeks of 65438+ 10/month and whether it is a leap year, can we launch an annual calendar. Then, only from the date and weeks of the Gregorian calendar, there are only 14 different versions of the calendar, so the probability of a calendar "crashing" in a certain biennium is still very high. For example, the calendars of 1997 and 2003 are exactly the same as those of 20 14.

The calendar of 20 14, like the calendar of 1986, also inspired the nostalgic enthusiasm of netizens. The reporter found in online stores such as Taobao that things like "1986 calendar sample reduction and passbook out of print" were sold at 180 yuan. Many netizens said that giving or collecting desk calendars, calendar greeting cards and ephemeris 28 years ago has special commemorative significance for birthdays, weddings and other dates, and the meaning of "going back in time" has also become a clever blessing.