Type of year A on a solar calendar according to its starting and ending days in the week
A common year starting on Sunday is any non-leap year (i.e. a year with 365 days) that begins on Sunday, 1 January, and ends on Sunday, 31 December. Its dominical letter hence is A. The current year, 2023, is a common year starting on Sunday in the Gregorian calendar. The last such year was 2017 and the next one will be 2034 in the Gregorian calendar, or, likewise, 2018 and 2029 in the obsolete Julian calendar, see below for more.
Any common year that starts on Sunday, Monday or Tuesday has two Friday the 13ths: those two in this common year occur in January and October.
This is the only common year with three occurrences of Friday the 17th: those three in this common year occur in February, March, and November. Leap years starting on Wednesday share this characteristic, for the months January, April and July. From February until March in this type of year is also the shortest period (one month) that runs between two instances of Friday the 17th.
Calendars
Calendar for any common year starting on Sunday, presented as common in many English-speaking areas |
---|
|
January
|
|
Su
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
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
|
|
|
|
|
February
|
|
Su
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
|
|
|
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 |
|
|
|
|
|
|
|
March
|
|
Su
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
|
|
|
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
|
|
|
|
|
April
|
|
Su
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
|
|
|
|
|
|
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 |
|
|
|
|
May
|
|
Su
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
|
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
|
|
|
|
|
June
|
|
Su
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
|
|
|
|
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 |
|
|
|
|
July
|
|
Su
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
|
|
|
|
|
|
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
|
|
|
|
August
|
|
Su
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
|
|
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
|
|
|
|
|
September
|
|
Su
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
|
|
|
|
|
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
|
|
|
|
|
October
|
|
Su
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
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
|
|
|
|
|
November
|
|
Su
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
|
|
|
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 |
|
|
|
|
|
December
|
|
Su
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
|
|
|
|
|
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 Sunday (dominical letter A) |
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|
January
|
|
Wk
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
Su
|
52
|
|
|
|
|
|
|
01
|
01
|
02 |
03 |
04 |
05 |
06 |
07 |
08
|
02
|
09 |
10 |
11 |
12 |
13 |
14 |
15
|
03
|
16 |
17 |
18 |
19 |
20 |
21 |
22
|
04
|
23 |
24 |
25 |
26 |
27 |
28 |
29
|
05
|
30 |
31
|
|
|
|
February
|
|
Wk
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
Su
|
05
|
|
|
01 |
02 |
03 |
04 |
05
|
06
|
06 |
07 |
08 |
09 |
10 |
11 |
12
|
07
|
13 |
14 |
15 |
16 |
17 |
18 |
19
|
08
|
20 |
21 |
22 |
23 |
24 |
25 |
26
|
09
|
27 |
28 |
|
|
|
|
|
|
|
|
March
|
|
Wk
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
Su
|
09
|
|
|
01 |
02 |
03 |
04 |
05
|
10
|
06 |
07 |
08 |
09 |
10 |
11 |
12
|
11
|
13 |
14 |
15 |
16 |
17 |
18 |
19
|
12
|
20 |
21 |
22 |
23 |
24 |
25 |
26
|
13
|
27 |
28 |
29 |
30 |
31
|
|
|
|
|
|
April
|
|
Wk
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
Su
|
13
|
|
|
|
|
|
01 |
02
|
14
|
03 |
04 |
05 |
06 |
07 |
08 |
09
|
15
|
10 |
11 |
12 |
13 |
14 |
15 |
16
|
16
|
17 |
18 |
19 |
20 |
21 |
22 |
23
|
17
|
24 |
25 |
26 |
27 |
28 |
29 |
30
|
|
|
|
|
May
|
|
Wk
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
Su
|
18
|
01 |
02 |
03 |
04 |
05 |
06 |
07
|
19
|
08 |
09 |
10 |
11 |
12 |
13 |
14
|
20
|
15 |
16 |
17 |
18 |
19 |
20 |
21
|
21
|
22 |
23 |
24 |
25 |
26 |
27 |
28
|
22
|
29 |
30 |
31
|
|
|
|
|
|
June
|
|
Wk
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
Su
|
22
|
|
|
|
01 |
02 |
03 |
04
|
23
|
05 |
06 |
07 |
08 |
09 |
10 |
11
|
24
|
12 |
13 |
14 |
15 |
16 |
17 |
18
|
25
|
19 |
20 |
21 |
22 |
23 |
24 |
25
|
26
|
26 |
27 |
28 |
29 |
30 |
|
|
|
|
|
|
July
|
|
Wk
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
Su
|
26
|
|
|
|
|
|
01 |
02
|
27
|
03 |
04 |
05 |
06 |
07 |
08 |
09
|
28
|
10 |
11 |
12 |
13 |
14 |
15 |
16
|
29
|
17 |
18 |
19 |
20 |
21 |
22 |
23
|
30
|
24 |
25 |
26 |
27 |
28 |
29 |
30
|
31
|
31
|
|
|
|
August
|
|
Wk
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
Su
|
31
|
|
01 |
02 |
03 |
04 |
05 |
06
|
32
|
07 |
08 |
09 |
10 |
11 |
12 |
13
|
33
|
14 |
15 |
16 |
17 |
18 |
19 |
20
|
34
|
21 |
22 |
23 |
24 |
25 |
26 |
27
|
35
|
28 |
29 |
30 |
31
|
|
|
|
|
|
September
|
|
Wk
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
Su
|
35
|
|
|
|
|
01 |
02 |
03
|
36
|
04 |
05 |
06 |
07 |
08 |
09 |
10
|
37
|
11 |
12 |
13 |
14 |
15 |
16 |
17
|
38
|
18 |
19 |
20 |
21 |
22 |
23 |
24
|
39
|
25 |
26 |
27 |
28 |
29 |
30 |
|
|
|
|
|
October
|
|
Wk
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
Su
|
39
|
|
|
|
|
|
|
01
|
40
|
02 |
03 |
04 |
05 |
06 |
07 |
08
|
41
|
09 |
10 |
11 |
12 |
13 |
14 |
15
|
42
|
16 |
17 |
18 |
19 |
20 |
21 |
22
|
43
|
23 |
24 |
25 |
26 |
27 |
28 |
29
|
44
|
30 |
31
|
|
|
|
November
|
|
Wk
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
Su
|
44
|
|
|
01 |
02 |
03 |
04 |
05
|
45
|
06 |
07 |
08 |
09 |
10 |
11 |
12
|
46
|
13 |
14 |
15 |
16 |
17 |
18 |
19
|
47
|
20 |
21 |
22 |
23 |
24 |
25 |
26
|
48
|
27 |
28 |
29 |
30 |
|
|
|
|
|
|
December
|
|
Wk
|
Mo
|
Tu
|
We
|
Th
|
Fr
|
Sa
|
Su
|
48
|
|
|
|
|
01 |
02 |
03
|
49
|
04 |
05 |
06 |
07 |
08 |
09 |
10
|
50
|
11 |
12 |
13 |
14 |
15 |
16 |
17
|
51
|
18 |
19 |
20 |
21 |
22 |
23 |
24
|
52
|
25 |
26 |
27 |
28 |
29 |
30 |
31
|
|
|
|
Applicable years
Gregorian Calendar
In the (currently used) Gregorian calendar, alongside Monday, Wednesday, Friday or Saturday, the fourteen types of year (seven common, seven leap) repeat in a 400-year cycle (20871 weeks). Forty-three common years per cycle or exactly 10.75% start on a Sunday. The 28-year sub-cycle only spans across century years divisible by 400, e.g. 1600, 2000, and 2400.
400-year cycle
0–99
|
6 |
17 |
23 |
34 |
45 |
51 |
62 |
73 |
79 |
90 |
|
100–199
|
102 |
113 |
119 |
130 |
141 |
147 |
158 |
169 |
175 |
186 |
197
|
200–299
|
209 |
215 |
226 |
237 |
243 |
254 |
265 |
271 |
282 |
293 |
299
|
300–399
|
305 |
311 |
322 |
333 |
339 |
350 |
361 |
367 |
378 |
389 |
395
|
Julian Calendar
In the now-obsolete Julian calendar, the fourteen types of year (seven common, seven leap) repeat in a 28-year cycle (1461 weeks). A leap year has two adjoining dominical letters (one for January and February and the other for March to December, as 29 February has no letter). This sequence occurs exactly once within a cycle, and every common letter thrice.
As the Julian calendar repeats after 28 years that means it will also repeat after 700 years, i.e. 25 cycles. The year's position in the cycle is given by the formula ((year + 8) mod 28) + 1). Years 11, 22 and 28 of the cycle are common years beginning on Sunday. 2017 is year 10 of the cycle. Approximately 10.71% of all years are common years beginning on Sunday.
Julian common years starting on Sunday
Decade
|
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
8th |
9th |
10th
|
15th century
|
1402 |
1413 |
1419 |
1430 |
— |
1441 |
1447 |
1458 |
1469 |
1475 |
1486 |
1497
|
16th century
|
1503 |
1514 |
1525 |
1531 |
1542 |
1553 |
1559 |
1570 |
— |
1581 |
1587 |
1598
|
17th century
|
1609 |
1615 |
1626 |
1637 |
1643 |
1654 |
1665 |
1671 |
1682 |
1693 |
1699
|
18th century
|
1710 |
— |
1721 |
1727 |
1738 |
1749 |
1755 |
1766 |
1777 |
1783 |
1794
|
19th century
|
1805 |
1811 |
1822 |
1833 |
1839 |
1850 |
— |
1861 |
1867 |
1878 |
1889 |
1895
|
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
|
Holidays
International
Roman Catholic Solemnities
Australia and New Zealand
British Isles
Canada
United States
|
---|
Year starts
|
|
Common years
|
|
Leap years
|
1 Jan |
Count |
Ratio
|
31 Dec |
DL |
DD |
Count |
Ratio
|
31 Dec |
DL |
DD |
Count |
Ratio
|
Sun
|
58 |
14.50 %
|
Sun |
A |
Tue |
43 |
10.75 %
|
Mon |
AG |
Wed |
15 |
03.75 %
|
Sat
|
56 |
14.00 %
|
Sat |
B |
Mon |
43 |
10.75 %
|
Sun |
BA |
Tue |
13 |
03.25 %
|
Fri
|
58 |
14.50 %
|
Fri |
C |
Sun |
43 |
10.75 %
|
Sat |
CB |
Mon |
15 |
03.75 %
|
Thu
|
57 |
14.25 %
|
Thu |
D |
Sat |
44 |
11.00 %
|
Fri |
DC |
Sun |
13 |
03.25 %
|
Wed
|
57 |
14.25 %
|
Wed |
E |
Fri |
43 |
10.75 %
|
Thu |
ED |
Sat |
14 |
03.50 %
|
Tue
|
58 |
14.50 %
|
Tue |
F |
Thu |
44 |
11.00 %
|
Wed |
FE |
Fri |
14 |
03.50 %
|
Mon
|
56 |
14.00 %
|
Mon |
G |
Wed |
43 |
10.75 %
|
Tue |
GF |
Thu |
13 |
03.25 %
|
∑
|
400 |
100.0 %
|
|
303 |
75.75 %
|
|
97 |
24.25 %
|
|
|