# How often in years do calendars repeat with the same day-date combinations?

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Calendars repeat in a regular cycle, at least within a century, because each year has 1 day more than exactly 52 weeks, and leap years add another extra day . This combination results in a sequence of repeated calendars in a 28-year cycle. For NON-LEAP YEARS, a given arrangement of days will repeat in 6 years, then 11, then 11 years, then begin a new cycle. Crossing a century changes this because only every 4th century year (e.g. 2000 but not 2100, 2200, or 2300) is a leap year. LEAP YEAR calendars repeat every 28 years.

When Calendars repeat
There is a very simple pattern for determining "when" calendars repeat with the same day/date combinations. Define any year as one of four things: a "leap year", the "1st year after a leap year", the "2nd year after a leap year", or the "3rd year after a leap year". Add 28 to a "leap year" to get the next year that it will repeat. Add 6 to the "1st year after a leap year" to get the next year that it will repeat; add 11 to the "2nd year after a leap year" to get the next year that it will repeat. Also add 11 to the "3rd year after a leap year" to get the next year that it repeats. Ex: 2010 is the 2nd yr after a leap year and will repeat in 2010 + 11 = 2021. 2011 repeats in 2022; 2012 repeats in 2040; 2013 repeats in 2019; 2014 repeats in 2025; 2015 repeats in 2026; 2016 repeats in 2044; 2017 repeats in 2023; and so on.

How often calendars repeat
• Any leap year calendar will repeat in exactly the same way every 28 years.
• Any "1st year after a leap year" will repeat in a 6-11-11 cycle, ie, it will repeat in 6 years, then come up again in 11 years, come up again in 11 more years, then repeat the 6-11-11 year cycle.
• Both "2nd year after a leap year" and "3rd year after a leap year" will repeat in an 11-11-6 cycle.

Notice the patterns involve 6, 11, and 28. The cycles of 6-11-11 and 11-11-6 add to 28.

It can be 5, 6, or 11 years before an individual date-day combination comes up again. Individual days will repeat on a 6, 5, 6, 11 year cycle. For example, January 1, 2000 (a leap year) was a Saturday. The years that January 1 fell on or will fall on Saturday are: 1955, 1966, 1972, 1977, 1983, 1994, 2000, 2005, 2011, 2022, 2028, 2033, 2039, and 2050.

Possible Calendars
There are 14 possible combinations:
A year can begin on one of 7 weekdays, and the year can be a regular year or a leap year.
Note that the cycle doesn't repeat on a 14 year basis. Because the year can start on one of 7 days, and a leap year comes every 4 years, the cycle is more complicated, but any given year can have its calendar taken from one of the 14 possible calendars.
In a regular (non-leap) year, the year ends on the same day of the week as it starts (2005 started on Saturday, and will end on Saturday) That's 52 weeks and one day. The next year starts on the next day of the week, and should end on that same weekday. (2006 starts on a Sunday, and ends on a Sunday.)
A leap year will end on the weekday immediately after the weekday on which it starts, and is 52 weeks and 2 days long. (2004 started on a Thursday, and ended on a Friday).
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# When will 1954 calendar year repeat?

1954 was a common year starting on Friday. As of 2012, the next time such a year will happen is in 2021.

# When will the calendar year 2006 repeat?

2006, 2017, 2023, 2034, 2045, 2051, 2062, 2073, 2079, 2090, 2102, 2113, 2119.

# How often will a calendar repeat itself?

This is variable, it depends on the way leap years fall in between any two given years. For example, Christmas of 1990 was a Tuesday but because of the occurrence of the lea

# When will the 1988 calendar year repeat?

1988 calendar year will repeat in 2016.

2013 and 2019

# When will the 1971 calendar year repeat?

1971 was a common year starting on Friday. The next such year, as of 2011, will be 2021.

2021

# When does the 2007 calendar year repeat?

Taking the rest of the 21st century, 2007 will repeat in the years2018, 2029, 2035, 2046, 2057, 2063, 2074, 2085 and 2091.

# Will a 1966 calendar repeat with the same day-date combinations?

Yes it will. All calendars do. Since then, 1966 repeated in: 1977, 1983, 1994, 2005 and 2011.

# What year will calendar repeat month day year numbers?

Given the question was asked in 2012, the next time 2012's calendar will be repeated exactly, given that it is a leap year, is not until 2040. Given the question was asked in

# When will the 2012 calendar year repeat?

The calendar year will be the same in 2040.

# When will the 2013 calendar year repeat?

2019, 2030, 2041, 2047, 2058.
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2014
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# Why do certain calendars repeat after 50 years - 2017 will have the same day-date arrangement as 1967?

Calendar years repeat more often than that and not every year willrepeat 50 years later. 2013 and 2063 have different arrangementsfor example. A year can repeat after 5 years,
In Calendar

# Why do certain calendars repeat after 17 years - 2022 and 2023 will be the same as 2005 and 2006?

Calendars can repeat after either 5 years, 6 years or 11 years. So if there is a repetition after 6 years and again after 11 years, that will be at total of 17 years. 2005 rep
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# Is 2013 calendar a repeat from which year?

2002 was the last time the calendar was the same as in 2013.
In Calendar

# What year will 2014 calendar repeat?

2025, 2031, 2042, 2053, 2059, 2070, 2081, 2087 and 2098.