Common year starting on Monday

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A common year starting on Monday is any non-leap year (i.e. a year with 365 days) that begins on Monday, 1 January, and ends on Monday, 31 December. Its dominical letter hence is G. The most recent year of such kind was 2007 and the next one will be 2018 in the Gregorian calendar[1] or, likewise, 2013 and 2019 in the obsolete Julian calendar. The exceptional common year, 1900, was also a year of such kind, see below for more. Any common year that starts on Sunday, Monday or Tuesday have two Friday the 13ths.

Calendars[edit]

Calendar for any common year starting on Monday,
presented as common in many English-speaking areas

01 02 03 04 05 06
07 08 09 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30 31  
 
01 02 03
04 05 06 07 08 09 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28
 
01 02 03
04 05 06 07 08 09 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30 31
 
01 02 03 04 05 06 07
08 09 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30  
 
01 02 03 04 05
06 07 08 09 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30 31  
 
01 02
03 04 05 06 07 08 09
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
 
01 02 03 04 05 06 07
08 09 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31  
 
01 02 03 04
05 06 07 08 09 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31  
 
01
02 03 04 05 06 07 08
09 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30  
01 02 03 04 05 06
07 08 09 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30 31  
 
01 02 03
04 05 06 07 08 09 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30
 
01
02 03 04 05 06 07 08
09 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30 31  


ISO 8601-conformant calendar with week numbers for
any common year starting on Monday (dominical letter G)

01 02 03 04 05 06 07
08 09 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31  
 
01
02 03 04 05 06 07 08
09 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30  
01
02 03 04 05 06 07 08
09 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30 31  
01 02 03 04 05 06 07
08 09 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31  
 
01 02 03 04
05 06 07 08 09 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28  
 
01 02 03 04 05 06
07 08 09 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30 31  
 
01 02 03 04 05
06 07 08 09 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30 31  
 
01 02 03 04
05 06 07 08 09 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30  
 
01 02 03 04
05 06 07 08 09 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31  
 
01 02 03
04 05 06 07 08 09 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30
 
01 02
03 04 05 06 07 08 09
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
 
01 02
03 04 05 06 07 08 09
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31  

Applicable years[edit]

Gregorian Calendar[edit]

In the (currently used) Gregorian calendar, the 15 types of years repeat in a 400-year cycle (20871 weeks). Forty-three common years per cycle or exactly 10.75% start on a Monday. The 28-year sub-cycle does only span across century years divisible by 400, e.g. 1600, 2000, and 2400.

Gregorian common years starting on Monday[1]
Decade 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th
16th century prior to first adoption (proleptic) 1590
17th century 1601 1607 1618 1629 1635 1646 1657 1663 1674 1685 1691
18th century 1703 1714 1725 1731 1742 1753 1759 1770 1781 1787 1798
19th century 1810 1821 1827 1838 1849 1855 1866 1877 1883 1894 1900
20th century 1906 1917 1923 1934 1945 1951 1962 1973 1979 1990
21st century 2001 2007 2018 2029 2035 2046 2057 2063 2074 2085 2091

Julian Calendar[edit]

In the now-obsolete Julian calendar, the 15 types of years repeat in a 28-year cycle (1461 weeks). Each leap-year dominical letter occurs exactly once and every common letter thrice.

Sequence of year types in the Julian calendar
Year 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
DL G F E DC B* A G FE D C B AG F E D CB A G F ED C B A GF E D C BA
1 Jan Mo Tu We Th Sa Su Mo Tu Th Fr Sa Su Tu We Th Fr Su Mo Tu We Fr Sa Su Mo We Th Fr Sa
31 Dec Fr We Mo Sa Th Tu Su

The final two digits of Julian years repeat after 700 years, i.e. 25 cycles. When starting to count in 2001 for instance, every 1st, 7th and 18th year of these Julian cycles is a common year that starts on a Monday, i.e. ca. 10.71 % of all years. They are always 6 or 11 years apart.

Julian common years starting on Monday
Decade 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th
15th century 1403 1414 1425 1431 1442 1453 1459 1470 1481 1487 1498
16th century 1509 1515 1526 1537 1543 1554 1565 1571 1582 1593 1599
17th century 1610 1621 1627 1638 1649 1655 1666 1677 1683 1694
18th century 1705 1711 1722 1733 1739 1750 1761 1767 1778 1789 1795
19th century 1806 1817 1823 1834 1845 1851 1862 1873 1879 1890
20th century 1901 1907 1918 1929 1935 1946 1957 1963 1974 1985 1991
21st century 2002 2013 2019 2030 2041 2047 2058 2069 2075 2086 2097

References[edit]

  1. ^ a b Robert van Gent (2005). "The Mathematics of the ISO 8601 Calendar". Utrecht University, Department of Mathematics. 
  2. ^ Robert H. van Gent (2005). "Mathematics of the ISO calendar". Department of Mathematics at Utrecht University.