Leap year starting on Wednesday

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A leap year starting on Wednesday is any year with 366 days (i.e. it includes 29 February) that begins on Wednesday 1 January and ends on Thursday 31 December. Its dominical letters hence are ED. The most recent year of such kind was 2020 and the next one will be 2048 in the Gregorian calendar, or likewise, 2004 and 2032 in the obsolete Julian calendar, see below for more. [1]

Contents

Any leap year that starts on Monday, Wednesday or Thursday has two Friday the 13ths: those two in this leap year occur in March and November. Common years starting on Thursday share this characteristic, but also have another in February.

This is the only leap year with three occurrences of Friday the 17th: those three in this leap year occur three months (13 weeks) apart: in January, April, and July. Common years starting on Sunday share this characteristic, in the months of February, March, and November.

From August of the common year preceding that year until October in this type of year is also the longest period (14 months) that occurs without a Tuesday the 13th. Common years starting on Saturday share this characteristic, from July of the year that precedes it to September in that type of year.

Calendars

Calendar for any leap year starting on Wednesday,
presented as common in many English-speaking areas
January
SuMoTuWeThFrSa
01020304
05060708091011
12131415161718
19202122232425
262728293031 
 
February
SuMoTuWeThFrSa
01
02030405060708
09101112131415
16171819202122
23242526272829
 
March
SuMoTuWeThFrSa
01020304050607
08091011121314
15161718192021
22232425262728
293031 
 
April
SuMoTuWeThFrSa
01020304
05060708091011
12131415161718
19202122232425
2627282930 
 
May
SuMoTuWeThFrSa
0102
03040506070809
10111213141516
17181920212223
24252627282930
31 
June
SuMoTuWeThFrSa
010203040506
07080910111213
14151617181920
21222324252627
282930 
 
July
SuMoTuWeThFrSa
01020304
05060708091011
12131415161718
19202122232425
262728293031 
 
August
SuMoTuWeThFrSa
01
02030405060708
09101112131415
16171819202122
23242526272829
3031 
September
SuMoTuWeThFrSa
0102030405
06070809101112
13141516171819
20212223242526
27282930 
 
October
SuMoTuWeThFrSa
010203
04050607080910
11121314151617
18192021222324
25262728293031
 
November
SuMoTuWeThFrSa
01020304050607
08091011121314
15161718192021
22232425262728
2930 
 
December
SuMoTuWeThFrSa
0102030405
06070809101112
13141516171819
20212223242526
2728293031 
 
ISO 8601-conformant calendar with week numbers for
any leap year starting on Wednesday (dominical letter ED)
January
WkMoTuWeThFrSaSu
010102030405
0206070809101112
0313141516171819
0420212223242526
052728293031 
  
February
WkMoTuWeThFrSaSu
050102
0603040506070809
0710111213141516
0817181920212223
09242526272829
  
March
WkMoTuWeThFrSaSu
0901
1002030405060708
1109101112131415
1216171819202122
1323242526272829
143031 
April
WkMoTuWeThFrSaSu
140102030405
1506070809101112
1613141516171819
1720212223242526
1827282930 
  
May
WkMoTuWeThFrSaSu
18010203
1904050607080910
2011121314151617
2118192021222324
2225262728293031
  
June
WkMoTuWeThFrSaSu
2301020304050607
2408091011121314
2515161718192021
2622232425262728
272930 
  
July
WkMoTuWeThFrSaSu
270102030405
2806070809101112
2913141516171819
3020212223242526
312728293031 
  
August
WkMoTuWeThFrSaSu
310102
3203040506070809
3310111213141516
3417181920212223
3524252627282930
3631 
September
WkMoTuWeThFrSaSu
36010203040506
3707080910111213
3814151617181920
3921222324252627
40282930 
  
October
WkMoTuWeThFrSaSu
4001020304
4105060708091011
4212131415161718
4319202122232425
44262728293031 
  
November
WkMoTuWeThFrSaSu
4401
4502030405060708
4609101112131415
4716171819202122
4823242526272829
4930 
December
WkMoTuWeThFrSaSu
49010203040506
5007080910111213
5114151617181920
5221222324252627
5328293031 
  

Applicable years

Gregorian Calendar

Leap years that begin on Wednesday, along with those starting on Tuesday, occur at a rate of approximately 14.43% (14 out of 97) of all total leap years in a 400-year cycle of the Gregorian calendar. Thus, their overall occurrence is 3.5% (14 out of 400).

For this kind of year, the corresponding ISO year has 53 weeks.

Gregorian leap years starting on Wednesday [1]
Decade1st2nd3rd4th5th6th7th8th9th10th
16th century prior to first adoption (proleptic) 1592
17th century 1620 1648 1676
18th century 1716 1744 1772
19th century 1812 1840 1868 1896
20th century 1908 1936 1964 1992
21st century 2020 2048 2076
22nd century 2116 2144 2172
23rd century 2212 2240 2268 2296
24th century 2308 2336 2364 2392
25th century 2420 2448 2476
26th century 2516 2544 2572
27th century 2612 2640 2668 2696
400-year cycle
0–99204876
100–199116144172
200–299212240268296
300–399308336364392

Julian Calendar

Like all leap year types, the one starting with 1 January on a Wednesday 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 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).

Julian leap years starting on Wednesday
Decade1st2nd3rd4th5th6th7th8th9th10th
15th century 1416 1444 1472 1500
16th century 1528 1556 1584
17th century 1612 1640 1668 1696
18th century 1724 1752 1780
19th century 1808 1836 1864 1892
20th century 1920 1948 1976
21st century 2004 2032 2060 2088
22nd century 2116 2144 2172 2200

Holidays

International

Roman Catholic Solemnities

Australia and New Zealand

British Isles

Canada

United States

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References

  1. 1 2 Robert van Gent (2017). "The Mathematics of the ISO 8601 Calendar". Utrecht University, Department of Mathematics. Retrieved 20 July 2017.