A leap year starting on Sunday is any year with 366 days (i.e. it includes 29 February) that begins on Sunday, 1 January, and ends on Monday, 31 December. Its dominical lettershence are AG. The most recent year of such kind was 2012 and the next one will be 2040 in the Gregorian calendar or, likewise, 1996 and 2024 in the obsolete Julian calendar.
This is the only leap year with three occurrences of Friday the 13th. Any common year starting on a Thursday shares this characteristic. The instances of Friday the 13th in this leap year are three months (13 weeks) apart: in January, April, and July. With the exception of skipped leap years, leap years starting on a Sunday falls exactly three years either side of two consecutive common years starting on Thursday – for example 2012 between 2009 and 2015. This leap year also has the shortest gap between Leap Day (February 29) and the start of Daylight Saving Time in Europe, only by 25 days. In this leap year, the leap day, U.S. Independence Day, and Halloween are on a Wednesday, Memorial Day is on May 28, Labor Day is on September 3, Thanksgiving is on its earliest possible date (November 22), and Christmas is on a Tuesday.
In this type of year, all dates (except 29 February) fall on their respective weekdays 58 times in the 400 year Gregorian calendar cycle. Leap years starting on Friday share this characteristic.
Calendars
Calendar for any leap year starting on Sunday,
presented as common in many English-speaking areas |
|
January |
|
| Su |
Mo |
Tu |
We |
Th |
Fr |
Sa |
| 1 |
2 |
3 |
4 |
5 |
6 |
7 |
| 8 |
9 |
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 |
|
|
|
1 |
2 |
3 |
4 |
| 5 |
6 |
7 |
8 |
9 |
10 |
11 |
| 12 |
13 |
14 |
15 |
16 |
17 |
18 |
| 19 |
20 |
21 |
22 |
23 |
24 |
25 |
| 26 |
27 |
28 |
29 |
|
|
|
|
|
|
March |
|
| Su |
Mo |
Tu |
We |
Th |
Fr |
Sa |
|
|
|
|
1 |
2 |
3 |
| 4 |
5 |
6 |
7 |
8 |
9 |
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 |
| 1 |
2 |
3 |
4 |
5 |
6 |
7 |
| 8 |
9 |
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 |
|
|
1 |
2 |
3 |
4 |
5 |
| 6 |
7 |
8 |
9 |
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 |
|
|
|
|
|
1 |
2 |
| 3 |
4 |
5 |
6 |
7 |
8 |
9 |
| 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 |
| 1 |
2 |
3 |
4 |
5 |
6 |
7 |
| 8 |
9 |
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 |
|
|
|
1 |
2 |
3 |
4 |
| 5 |
6 |
7 |
8 |
9 |
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 |
|
|
|
|
|
|
1 |
| 2 |
3 |
4 |
5 |
6 |
7 |
8 |
| 9 |
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 |
|
1 |
2 |
3 |
4 |
5 |
6 |
| 7 |
8 |
9 |
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 |
|
|
|
|
1 |
2 |
3 |
| 4 |
5 |
6 |
7 |
8 |
9 |
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 |
|
|
|
|
|
|
1 |
| 2 |
3 |
4 |
5 |
6 |
7 |
8 |
| 9 |
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 leap year starting on Sunday (dominical letter AG) |
|
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 |
29 |
|
|
|
|
|
|
|
March |
|
| Wk |
Mo |
Tu |
We |
Th |
Fr |
Sa |
Su |
| 09 |
|
|
|
01 |
02 |
03 |
04 |
| 10 |
05 |
06 |
07 |
08 |
09 |
10 |
11 |
| 11 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
| 12 |
19 |
20 |
21 |
22 |
23 |
24 |
25 |
| 13 |
26 |
27 |
28 |
29 |
30 |
31 |
|
|
|
|
|
April |
|
| Wk |
Mo |
Tu |
We |
Th |
Fr |
Sa |
Su |
| 13 |
|
|
|
|
|
|
01 |
| 14 |
02 |
03 |
04 |
05 |
06 |
07 |
08 |
| 15 |
09 |
10 |
11 |
12 |
13 |
14 |
15 |
| 16 |
16 |
17 |
18 |
19 |
20 |
21 |
22 |
| 17 |
23 |
24 |
25 |
26 |
27 |
28 |
29 |
| 18 |
30 |
|
|
|
|
May |
|
| Wk |
Mo |
Tu |
We |
Th |
Fr |
Sa |
Su |
| 18 |
|
01 |
02 |
03 |
04 |
05 |
06 |
| 19 |
07 |
08 |
09 |
10 |
11 |
12 |
13 |
| 20 |
14 |
15 |
16 |
17 |
18 |
19 |
20 |
| 21 |
21 |
22 |
23 |
24 |
25 |
26 |
27 |
| 22 |
28 |
29 |
30 |
31 |
|
|
|
|
|
June |
|
| Wk |
Mo |
Tu |
We |
Th |
Fr |
Sa |
Su |
| 22 |
|
|
|
|
01 |
02 |
03 |
| 23 |
04 |
05 |
06 |
07 |
08 |
09 |
10 |
| 24 |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
| 25 |
18 |
19 |
20 |
21 |
22 |
23 |
24 |
| 26 |
25 |
26 |
27 |
28 |
29 |
30 |
|
|
|
|
|
July |
|
| Wk |
Mo |
Tu |
We |
Th |
Fr |
Sa |
Su |
| 26 |
|
|
|
|
|
|
01 |
| 27 |
02 |
03 |
04 |
05 |
06 |
07 |
08 |
| 28 |
09 |
10 |
11 |
12 |
13 |
14 |
15 |
| 29 |
16 |
17 |
18 |
19 |
20 |
21 |
22 |
| 30 |
23 |
24 |
25 |
26 |
27 |
28 |
29 |
| 31 |
30 |
31 |
|
|
|
August |
|
| Wk |
Mo |
Tu |
We |
Th |
Fr |
Sa |
Su |
| 31 |
|
|
01 |
02 |
03 |
04 |
05 |
| 32 |
06 |
07 |
08 |
09 |
10 |
11 |
12 |
| 33 |
13 |
14 |
15 |
16 |
17 |
18 |
19 |
| 34 |
20 |
21 |
22 |
23 |
24 |
25 |
26 |
| 35 |
27 |
28 |
29 |
30 |
31 |
|
|
|
|
|
September |
|
| Wk |
Mo |
Tu |
We |
Th |
Fr |
Sa |
Su |
| 35 |
|
|
|
|
|
01 |
02 |
| 36 |
03 |
04 |
05 |
06 |
07 |
08 |
09 |
| 37 |
10 |
11 |
12 |
13 |
14 |
15 |
16 |
| 38 |
17 |
18 |
19 |
20 |
21 |
22 |
23 |
| 39 |
24 |
25 |
26 |
27 |
28 |
29 |
30 |
|
|
|
|
October |
|
| Wk |
Mo |
Tu |
We |
Th |
Fr |
Sa |
Su |
| 40 |
01 |
02 |
03 |
04 |
05 |
06 |
07 |
| 41 |
08 |
09 |
10 |
11 |
12 |
13 |
14 |
| 42 |
15 |
16 |
17 |
18 |
19 |
20 |
21 |
| 43 |
22 |
23 |
24 |
25 |
26 |
27 |
28 |
| 44 |
29 |
30 |
31 |
|
|
|
|
|
November |
|
| Wk |
Mo |
Tu |
We |
Th |
Fr |
Sa |
Su |
| 44 |
|
|
|
01 |
02 |
03 |
04 |
| 45 |
05 |
06 |
07 |
08 |
09 |
10 |
11 |
| 46 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
| 47 |
19 |
20 |
21 |
22 |
23 |
24 |
25 |
| 48 |
26 |
27 |
28 |
29 |
30 |
|
|
|
|
|
|
December |
|
| Wk |
Mo |
Tu |
We |
Th |
Fr |
Sa |
Su |
| 48 |
|
|
|
|
|
01 |
02 |
| 49 |
03 |
04 |
05 |
06 |
07 |
08 |
09 |
| 50 |
10 |
11 |
12 |
13 |
14 |
15 |
16 |
| 51 |
17 |
18 |
19 |
20 |
21 |
22 |
23 |
| 52 |
24 |
25 |
26 |
27 |
28 |
29 |
30 |
| 01 |
31 |
|
|
Applicable years
Gregorian Calendar
Leap years that begin on Sunday, along with those that start on Friday, occur most frequently: 15 out of the 97 (≈ 15.46%) total leap years in a 400-year cycle of the Gregorian calendar. Thus, the overall occurrence is 3.75% (15 out of 400).
Gregorian leap years starting on Sunday
| Decade |
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
8th |
9th |
10th |
| 17th century |
|
1612 |
|
|
1640 |
|
1668 |
|
|
1696 |
| 18th century |
1708 |
|
|
1736 |
|
|
1764 |
|
|
1792 |
| 19th century |
1804 |
|
|
1832 |
|
|
1860 |
|
1888 |
|
| 20th century |
|
|
1928 |
|
|
1956 |
|
|
1984 |
|
| 21st century |
|
2012 |
|
|
2040 |
|
2068 |
|
|
2096 |
| 22nd century |
2108 |
|
|
2136 |
|
|
2164 |
|
|
2192 |
Gregorian year types per leap cycle by Dominical letter (DL) and Doomsday (DD)
| 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 |
3.75 % |
| Sat |
56 |
14.00 % |
Sat |
B |
Mon |
43 |
10.75 % |
Sun |
BA |
Tue |
13 |
3.25 % |
| Fri |
58 |
14.50 % |
Fri |
C |
Sun |
43 |
10.75 % |
Sat |
CB |
Mon |
15 |
3.75 % |
| Thu |
57 |
14.25 % |
Thu |
D |
Sat |
44 |
11.00 % |
Fri |
DC |
Sun |
13 |
3.25 % |
| Wed |
57 |
14.25 % |
Wed |
E |
Fri |
43 |
10.75 % |
Thu |
ED |
Sat |
14 |
3.50 % |
| Tue |
58 |
14.50 % |
Tue |
F |
Thu |
44 |
11.00 % |
Wed |
FE |
Fri |
14 |
3.50 % |
| Mon |
56 |
14.00 % |
Mon |
G |
Wed |
43 |
10.75 % |
Tue |
GF |
Thu |
13 |
3.25 % |
| ∑ |
400 |
100.0 % |
|
303 |
75.75 % |
|
97 |
24.25 % |
Julian Calendar
Like all leap year types, the one starting with 1 January on a Sunday occurs exactly once in a 28-year cycle in the Julian calendar, i.e., in 3.57% of years. As the Julian calendar repeats after 28 years, it will also repeat after 700 years, i.e., 25 cycles. The formula gives the year’s position in the cycle ((year + 8) mod 28) + 1).
Julian leap years starting on Sunday
| Decade |
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
8th |
9th |
10th |
| 15th century |
1408 |
|
|
1436 |
|
|
1464 |
|
|
1492 |
| 16th century |
|
1520 |
|
|
1548 |
|
|
1576 |
|
|
| 17th century |
1604 |
|
|
1632 |
|
1660 |
|
|
1688 |
|
| 18th century |
|
1716 |
|
|
1744 |
|
|
1772 |
|
1800 |
| 19th century |
|
|
1828 |
|
|
1856 |
|
|
1884 |
|
| 20th century |
|
1912 |
|
1940 |
|
|
1968 |
|
|
1996 |
| 21st century |
|
|
2024 |
|
|
2052 |
|
2080 |
|
|
| 22nd century |
2108 |
|
|
2136 |
|
|
2164 |
|
|
2192 |
