It's a detail that usually escapes most people, but worth knowing better. If you're considering throwing away old calendars, maybe you want to think twice, because there's always a year when we can reuse them. If we base ourselves on the Gregorian structure, the total number of calendars is 14. This translates into a repetition of calendars every 28 years in the worst case, so if you have a design you really appreciate, in the future you'll be able to hang it again, guaranteed.
Some calendar designs are extraordinary. At the time, they were casual items, but today they've become collectibles. Online, you can find copies that demand a real fortune, and beyond their economic and historical value, math teaches us we can reuse them. It sounds absurd, but it's the pure truth. For example: The year 2019 is compatible with calendars from 2013, 2002, 1991, 1985, 1974, 1963, 1957, 1946, 1935, and 1929. Don't hesitate to test it! Go to Google Images, search for a calendar from these years, and compare the positions with the 2019 calendar. They're identical.
The 14 Possible Calendar Combinations
The Gregorian calendar has a maximum of 14 possible combinations. Every year must start on some day of the week, but that year can be leap or not, giving us the magic number 14. Years called 'normal' start and end on the same day of the week (2019 is one of them, with Tuesday 01-01 and Tuesday 31-12), but leap years break that (2020 will have a Wednesday 01-01 and a Thursday 31-12). There are multiple variants, however, the firmest value indicates that a calendar is reused every 28 years. Do you have a copy of the 1991 Nintendo calendar? Then you can use it today!
The most effective way to verify a calendar's reuse is by visiting the portal "When Can I Reuse This Calendar". There, it will tell you which years will be compatible with the current calendar, and which ones you can reuse as a replacement. Another interesting site is Time and Date, which dedicates an entire section to calendar recycling and offers a much more extensive analysis.
When Can I Reuse This Calendar: Click here
Time and Date: Click here
https://old.neoteo.com/calendario-holoceno-calendario-cientifico-centrado-humano/
